Hi! New member here, although I have been reading the page for advice for many weeks 
I’m looking for help with my cage setup as I feel overwhelmed by information. I have 2 male dwarf rabbits, Ozzy and Lemmy, age 12 weeks. They are separated right now, in cages next to each other until they can be neutered (in January) and bonded.They started out together as they were from the same litter, but I quickly spotted aggression and wanted to stop it before anything serious happened.
Attached to their cage is a playpen which they are free to run around in for at least 4-5 hours in the evening (more at the weekend). It is lined with carpet and they seem very happy with this. Eventually, when they are bonded and back together (hopefully!) they will have free reign of the room and be housed together in a larger setup.
My question is what to line the cage with? I’ve read so many different answers and very confused! Right now they have a thin layer of sawdust (not pine or cedar) and straw. They have a litter box with wood litter. We are still litter training them so lots of poop and pee in the cage, although they are slowly starting to use the litter box more and more.
Ozzy likes to make a patch and sleep on the bare plastic, but I don’t want to empty the entire cage of any bedding? I don’t think blankets are a good idea yet as our apartment can get warm plus they are still learning to not pee everywhere. Both of them will scratch and chew at the carpet in their playpen at times, even with lots of toys, so I don’t want to leave them with carpet unsupervised
I would really appreciate any advice!