Keep in mind that the temperature of the room, even near your fermenter, is likely to be 5-10 degrees cooler than the actual temperature inside the fermenter. So, a room at 75 degrees or more is likely to produce significant esters and other funny (but not deadly!) things in your brew.
If you feel like spending a fair amount, there are fermenters with cooling units that can bring the ambient temperature down 50 degrees from room (or garage, or outdoor) temperature. Of course, $1200 to $2500 is a bit of an investment, more than this happy camper can justify. (example: ). It is fun to dream, though! Perhaps someone who heats his home to 80 degrees can indulge in such extravagance!