I don't have any problem with living in the small space.  However, cold, rain and snow can be a problem.  I picked ABQ for the winter, which has been too cold, but fortunately dry.  Water and mud can be a real problem when you have no porch or entryway.  

 The biggest problem I ran into was scarcity of free camping, especially in cities.  I thought I would be able to find free or cheap parking somewhere, or at least use my friends' driveways.  From what I can tell, most of the E coast and midwest are very RV unfriendly, not just in cities, unless you pay near-motel prices per night.  Even in driveways, I was usually run off by an HOA or local law enforcement very quickly - even in my own home, in Jacksonville.  Everyone thinks of land in terms of $ made or invested, so even the idea of someone living for free or the slightest threat to property values seems to piss them off, and they rat you out.  In many cities you can't even use WalMart parking lots, either for the same reason, or because of competition with expensive RV parks that probably got the laws passed.  Things are a lot better out west, where there is lots of land, but even so, I wanted to live in ABQ for a while, and the best I could find is a spot that costs $350/mo plus utilities.