Mesh Wifi Router Placement

TL;DR: How bad is it to put a router in the closet?

For those that know about these things... 

Our old router has been acting up, and seeing as it is probably 10 years old at this point I just decided to replace it as it appears that there is a hardware issue that is eventually going to be unfixable. 

So I bought a Tenda MW3 set. Basically 3 routers, which should be way overkill for my house, which is what I want--should be able to get service in the garage now. I know the ideal placement of these, but the ideal placement is not possible. So, my question is... how bad is it to put a router in the closet? I know it is definitely not good, but that would make the easiest setup in terms of not having wires everywhere. I'm hoping that I'll be able to run an ethernet cord from the closet router (hub router) through the basement to the next router, but that is going to be a best-case scenario and may be impossible. The last router will be on its own, not hooked up via ethernet no matter what.

I see no problem with putting it in the closet. 

Depends on the materials that your house was built with. If it's "normal" US construction - stick built dry wall - putting the router in the closet shouldn't be that big a deal. Things tend to get a little more problematic when you're dealing with stone or concrete buildings.

Radio waves pass through wood and drywall very easily. If the closet has concrete walls that's not ideal but still not terrible. If it were metal or stone it would be a huge problem.

Sweet. I'll be able to get it off the ground there too, probably about 10 feet up.