What species of snakes and what are your desired brumation temperatures?
I'd also direct you to the species specific forum for help.
Heres some general advice on the topic.
Use a thermometer in the fridge, most are around 4C which is probably too cool for a lot of species. Perhaps it can be turned up to a little higher temp?
There should be enough oxygen in the fridge. Open it and check on them every day or two to circulate air. Inside the fridge the snakes would need to be in containers, with a small water dish, and some holes for air exchange. Deep substrate is usually a bonus as well.
Also remember that brumation is only necessary for breeding, so unless this is your desire, don't brumate them.
Lastly, if the fridge won't work, perhaps ask if you can keep them at your parents house, or a neighbors, or friends ect.
Ian