I mean besides the cabins, can you rent a camper there?

No. You can rent a cabin. You can rent a campsite for RV, trailer, or tent. But you can't rent the RV, trailer, or tent. However there are other places in the Orlando area that will rent you an RV and it's going to cost a lot more than $35 a night, plus the $42 to $98 per night campsite fee you pay to Disney. If you can't afford the cabin and there are a lot of you, think about getting a room in Wilderness Lodge with fridge and microwave plus a tent site for the extra people to sleep at. Banish the 12 to 17 year olds to the tent and have a little peace for a change.