So this blew up. Thank you for all the responses! I'll try to reply to some of the concerns, and also add some more of my own details, so many comments that I don't think I can respond directly to anyone though. This is going to be a wall of text, so I'll try to break it up as logically as possible.
Regarding having something to do, I am one of those people who cannot just sit around and do nothing, at least not for long. I don't have enough time for the hobbies I have now, and have a ton of things I'd like to try out. I have a suspicion money will be the limiting factor more than ideas of what to do. Travel is a big thing, and I'll address that later. One thing I'd like to experiment with is cultivating some desert plants, but time and space are not viable right now. Wouldn't mind volunteering with an animal shelter/rescue on occasion, too, but that is something I don't have time for right now, and I have a couple of antisocial cats that would not be happy with me doing any fostering. There is always the chance I could turn into a couch potato, but I doubt it. If I get that bored, I'll go back to work to fill in some of my spare time.
Healthcare - I agree with mtn that the current path of Medicare/health insurance is unsustainable, but could still outlast the time between my retirement and Medicare eligibility. Rough plan would be to go to my wife's insurance when I am not working, and if she and I are both not working before age 65, have to pay out of pocket on an exchange for insurance. Not ideal, as that would likely be one of our biggest expenses, even if we don't have major health surprise.
Life expenses/savings - For our income, we live pretty modestly, both saving a pretty good chunk toward retirement. About 30-35 % of my income goes directly to retirement funds. About 25% of my retirement is in Roth style investments, so we should be able to play the game pretty well to minimize taxes in retirement. We have a fairly small mortgage with about 6 years left. Due to how long ago I bought the house, cost for our three bedroom bi-level is about the same as renting a 2 bedroom apartment. We have a decent sized emergency fund to cover any maintenance issues. We each also save some money each year for ourselves. I don't have a ton of that, I have a car hobby, so I need to start picking up the pace if I fully quit at 55. Admittedly, using the 4% rule, it'd take us until I am over 60 to be able to replace income, assuming inflation does not get too out of hand. I'm operating more on the idea of 4% of what we actually spend, plus some extra for health insurance.
Continued work - I work remote (and did before COVID). If I were to stay with my current company, I could easily work out of a class B RV with a 5G modem during the week, and bum around the country. Would still be a bit limited in my travel until my wife retires, as I handle a lot of the household work. Slowly trying to reduce the amount of that that exists. If I were to switch to seasonal work at 50, I'd probably be picking up whatever I could that is not too rough on my body, and can cover as much of my current expenses as possible, but not actually save. I could possibly do some consulting work for software QA, but if I'm going to do that, I'd rather stick to my current job. I could also grab a few certifications, and sell myself as an analytics consultant. Regardless, I do want there to be a fairly hard stop for a regular job, not having to work in my 60's and beyond. If I could find a more "live to work" type job, maybe this would all change.
Travel - My wife and I both want to travel more. It is one of our biggest indulgences as we have earned more income. I'm more of a domestic road trip type, and while she enjoys them, she also has international destinations we like to go to. Before one of our cats got too sick, we'd switch off years for planning and paying for vacations. I figure in early retirement before we settle down, we'll probably be looking at 10-15K a year (in current dollars) of travel expense. I also like hiking in the desert a lot, so if I live somewhere near my favorite haunts, that'll cut down on travel expenses.
Home - This is a big question mark. Originally, we had planned on retiring to the desert west to a smallish house, and traveling at our leisure when the weather there was bad. With the climate issues(not judging the whole man-made vs natural causes, just watching the events/trends) getting worse in recent years, that is kind of up in the air. We may stay in SW Ohio, and just move to a ranch style house (we both want as few stairs as possible, with falls being a leading injury as people age), as even though the weather can be uncomfortable here, at least it is not likely to become unlivable in our lifetimes. Another possibility that we are starting to consider is owning a place out west, and maybe getting a condo in the Great Lakes area for late-spring/summertime. Would rather not have two places to pay for and take care of, though. That could push retirement off. We are keeping an eye on the real estate market and are in a position where if there was another real estate market crash, we could conceivably buy our retirement home and pay a management company to rent it out until we are ready to use it.
Random stuff/my mentality - My dad died at age 64. He did manage to retire at 55, but kept very busy anyway, and still didn't manage to get to a lot of the things he wanted to do. In general my family is long lived, but there does seem to be some prevalence of dementia, too. My eyesight sucks and is getting worse (no specific medical problem, just bad genetics, I guess). I don't know how long I've got, and I'd like to enjoy as much of what I have left as possible. I do worry about money, so have been through quite a few scenarios, and try to play things conservatively. Obviously, you can't plan for everything, but then I also think what if I just keep working and still end up having an expensive health problem. Yeah, I'll likely still have more money, but I will have sacrificed time, and then may not be able to be comfortable in whatever retirement I end up with.
I'm not as worried about the financial aspect of retirement, as I should have that pretty well covered, but for those who have retired, knowledge of any financial surprises (good or bad) is appreciated. Lifestyle changes and any pitfalls are the biggest thing I am curious about.
