My experience is that a short period of time (like, 30 at night, 40 in daytime) does not hurt. But a HARD freeze, even for short time, will cause a problem. One time I was in a state park on the coast in Washington State and it was a balmy 50 degrees and then it went to 30 all of a sudden, not predicted. Problems. but a gradual lowering for a brief time won't cause severe problems.
On the other hand, not a good idea to leave a space heater on for a long period of time (like, overnight) although I have done this..... WOuldn't do it for a week, though. Best to use furnace to keep heat but you will burn your propane quickly.
JJ only, my cat went to Rainbow Bridge July 2015
I love my Sunseeker, when I'm on a trip I don't wanna go home!!!"
Total days camping each year: AS MUCH AS POSSIBLE!