I’m debating moving everyone inside but if mom is pregnant again, from dads break out, then I need to have a place she can nest again. And I’m not sure I can accommodate that inside.
Rabbits can have bunnies in a nestbox full of hay or straw. A rabbit nestbox is usually about a foot wide and 18" long for large breeds, and smaller breeds can be fine with even less space. One important detail: the opening needs to be at the top, or the upper half of one side, so the bunnies don't crawl out when they are still tiny.
If you have a large enough cage, it's easy enough to just stick a nestbox in. (It can be made of wood or metal, or maybe even a cardboard box.)
The temps here are crazy. I think it’s the constant freezing of all the melt off that might be killing them. But I really have no idea. What do your all think? Bring them inside or is it better to leave them be?
I do not know what would be best in your case.
When I raised rabbits, they all lived outdoors, all the time.
The bunnies were born in a nestbox full of hay or straw, and generally did fine.
But you probably have a different climate than I did, so my experience may not be very helpful
My rabbits were always in raised cages with wire floors. I have read that bunnies with access to the ground can get sick & die from coccidiosis. You might want to look into that. (Because my rabbits never had it, I never learned much about it.)