I'll take a measurement of my garage door to let you know the minimum space required width-wise to get a TM in -- and mine's modified to be narrower, FYI.
As to sleeping, my 4-year olds don't like sleeping in the same bed in the TM, even though they share a bedroom at their request. So, this season I'm going to be experimenting with the possibility of bunk beds (of a sort). In the event that they don't work out (fairly unlikely
) my son is happy to sleep on the floor on an air mattress (therm-a-rest style) and my daughter takes the couch/bed.