I wouldn't worry about temp.  I used a Classic in a shed , as long as moisture isn't an issue too much then should be ok.  Ive pulled macs from barns and had them working so temps are not much of an issue.  Can always put a small fan on the side to blow air across if it ever gets too hot. The CRT's don't like to be turned on below freezing, much like florescent lights.  

At this age I would get as much use out of anywhere and everywhere as much as you can.