Our three Shelties and four cats think the MH is there second home. Cats find their place and sleep 20 hours a day. Our dogs were crate trained from puppies. We make sure they have had a good walk, poop, pee and drink before crating them. We make sure things are dark and cool. They are good for 6-7 hours. Then all heck breaks out when we return. More wiggling, pooping, peeing and a good walk. They are good till dinner and more of the same. We've had more than one neighbor comment on how quiet our dogs are while we are gone.
They key is consistency in routine and commands. They adapt to a smaller space just like we do. Make a nest and special place and you will be ok.