Need a priority consult! Sudden vibration

After spending 6 hours stuck in a plane on the tarmac in Newark yesterday  the Jeep developed a bad driveline vibration about 1 AM driving home.

It started as a come-and-go running 75mph. It felt like you eased of the edge of the road and hit the rumble strip. It faded in, lasted about 15 sec and faded out. Over the next 5 miles it kept occurring more frequently until it was constant and increased in severity. It was worse under power. I slowed to 60 and got of the interstate. Crawled under the truck at a station and nothing felt obviously loose. 

I nursed it home the last 15 miles on B roads. If you keep it under 45mph there's no vibration. It gets progressively worse over that. Worse under power. Engine speed doesnt effect it. Feels like it's in the front end, I mainly felt it in the floorboards, not in the steering.

I need the jeep for a weekend long bike event starting tonight so I have to fix it today.

I'm thinking a front driveshaft u-joint or the CV joint is going out. 

If it was the front diff I dont think it would be okay at 40mph?

What do you guys think?

Does it change with acceleration (application of power)?

Full time 4x4? AWD?

similar to this?  https://www.youtube.com/watch?v=LnLzIkdRZR8

Almost anything can cause it.   Check for loose balljoints, ala https://www.youtube.com/watch?v=DsiSTNe_AL8

Then proceed to checking driveshafts.

Then get your tires road force balanced. 

Chunk of ice/snow frozen to something that rotates? I've had that happen with wheels, but it could happen anywhere that spins, and given the weather it's the first thing I would look for.

Check your lug nuts first.  That's probably not it, but it's free and quick.

I would check tires first, lugnuts and see if a weight fell off.

Could also be a u joint. I got a junkyard fan straight across for a cd of my band once with a weird vibration that i couldnt figure out for the first few trips. Turns out the u joint was so worn that it machined itself sideways a bit causing vibration but would heat up and lock itself if you checked it right away, and as soon as you got to speed it would float back to the middle. Usually though you can check that by hitting the gas hard and letting off, if theres a clank its a u joint.

Okay, update. I put the truck up on 4 stands and let it run in drive. AWD so all 4 turning.

I watched all the drive shafts and they seem to run smooth, not jumpy. At rest they are all solid with no play.

One front tire seems to have a slight hop in it that the others dont. I suspect tread separation. I'm at the tire store now to have it checked.

If I hadn't been up till 2 am I would have thought to just put the spare on it while it was on the stands to test the theory. Instead i guess I'll wait an hour to have it checked.

If it is separated I'll run the full size spare and use the bad tire as a backup till they get my new tire in.

Btw,  no ice on the truck.