I have the same problem
Wherever I can find someplace cold...it's actually too cold. My attic is currently reading 7 degrees celcius and the basement isn't much cooler than the appartment so I'm just keeping them in the appartment in tubs with a towel draped over. his is how a breeder I got my big amel from does it and he has great success with his clutches. Just find someplace that'll stay coolish and quiet and make it a little darker with a towel or blanket and let them have a 'room temp' brumation rather than a cool brumation. As their metabolism will still be going a little they might loose a little weight but it shouldn't be much at all. I'm going away tomorrow and my boyfriend won't be here for the next 10 days, so it'll be extra nice and quiet for them. Good luck,
Adèle