I am relatively new to the forum, and I am still learning. I currently own 5 corn snakes of varying ages, and am in the same predicament sort of.
I live in Tampa FL and lately temps outside have been pretty cool at night. My rack is in the "Florida Room" that is unheated and ends up with temps usually around 60 degrees.
I am using heat tape to keep the warm side about 80-85 degrees also. Of the three youngsters that I have that I want to keep feeding, two of them still have a voracious appetite. My Okeetee however seems to have just slowed down. She is in her hide all the time, I think I have only seen her out once in the last two weeks. Normally I can count on a 3-4 day poop after a feed with these three. Just like clockwork, Calli however took 8 days the last time she fed.
She refused food the last two times, today she was out and about, very active, I tried to feed her and no problem. I think that she is just more sensitive than my others to the changing temps and light cycles of the winter and is in a semi-brumation. She is "special"
My thoughts would be to give your snake some time to adjust to its new surroundings as stress is a big hinderence to feeding, place a couple of hides throughout the temperature ranges of the housing that you have so your snake can autoregulate its temp, make sure that you have an ample supply of water as a snake can go a long time without food but a short time without water, get a good thermometer with a probe to make sure the temps that you are getting are accurate, spend a little time just observing to see if you notice anything out of the ordinary such as labored breathing or any illness, all the basics. If they are all there, your snake may just be a little more sensitive and "special" too.
Good Luck,
Rolf