?about having cage off of floor

I've read contradictory info about how the cage shouldn't be on the floor to avoid drafts. But then there's info on how to give g.p.s free range on the floor or give them an entire room and they are living on the floor all the time. This doesn't make sense to me. Can somebody clarify? Thanks for bearing with my many questions!

I think that usually the floor time is supervised and shorter than the time they spend in cages, so the cages need to be warmer. (You go out in the cold all the time, but you wouldn't want to sleep there, right?)

Also, with free range of rooms, I think these rooms should be checked for drafts before time. If you have more than one piggie, it's probably not THAT big a deal if the cage is on the floor if it's a LITTLE drafty, if they're caged together and they can cuddle up together, maybe in a little blanket thing, but for safety, they should probably be kept where you know they'll be warm.

-Dan III