Welcome to the forum!
Sounds like you've already gotten some good advice. My two cents would be that I like the stolons to be about an inch (~3 centimeters or so) when I plant chicks. They seem to have trouble getting started if they're under 2 centimeters in diameter, but they'll likely survive at even as small as a centimeter. You can always just leave them in the clump to, a well established reef can be quite attractive and should your large rosette bloom and die, the others will fill in the gap it leaves behind quickly. I only pluck chicks when I'm looking to spread the variety to a different location or to cover more ground.
I keep my winter buy's inside by a big south facing window till spring to sometimes, or at least till they're established. I'm not so sure what rabbits might do to them, but here in the city squirrels and birds are the problem. A thick gravel layer seems to stop them from plucking the rosettes or digging in the pots, might help with rabbits to. I keep my semps outdoors year round, theoretically most are hardy down to zone 5 or colder, but it's really case by case based on the variety and I find factors beyond temperature like moisture, soil, and sunlight are more of the issue. My semps are grown primarily in pots, I move them into the shade on 90F+ degree days to prevent roasting them and some of them need to be covered during the rainy months to prevent rot. They're a bit more sensitive in pots because the roots are more exposed to the weather, but they're tough plants and will probably survive no matter what you do. Don't be afraid to experiment and see what works in your climate! with 80 chicks it sounds like you've got plenty of backups! You should know however that the larger rosettes tend to be more sensitive than the smaller ones, so what works for a chick may not work for a mature hen.