2 cats 1 golden retriever & litter box

We just purchased a new 2015 Cedar Creek Hathaway 38RD which has all of the bells and whistles but not much open floor space so where do I put the litter box (There is a central vac under the first step so it can't go there) and the food dishes so the dog doesn't get fat off of cat food. There is carpet under the table so do not want to put litter box there and carpet in living room and bedroom. I'm stuck. We're brand new to this so our first trip will be loading up the cats and the dog and heading down to FLorida for the winter. Excited but nervous about the pets travelling.