i have a girl that has gone off feed for me every year since i got her. It started when she was 990 grams (so just shy of 1000). I was offering her food every 2 weeks, but honestly, i can tell when shes hungry. What i do now is defrost food for everyone i know will eat, if the ones that arent eating start looking hungry when i prescent, i offer them a rodent meant for someone else, if they take it i go defrost another for the original meals owner and everyone is good, they don't take it, it goes to its intended owner and i dont have to worry about wasting rodents.
This girl just went off feed for me this year (3 weeks in a row no food) so now she'll get offered 1x a month, or not at all if she dosen't seem hungry. She is a night time cage roamer, and my biggest one. she is ALWAYS moving around her cage at night.
As long as your snake is active at night and not during the day its all fine and dandy as long as her weight is keeping up.