You may wish to look into a set of ramps for your dogs.
We were at a campground a month ago, and one camper had a handicapped member of their family. They had a wheelchair ramp that was pretty elaborate and included a couple of "switch-backs" to get up to the RV's level.
Of course, you won't probably want anything nearly as elaborate, but there must be a way to make a simple ramp to attach to the underside of the door frame area to at least get the dogs to the inside steps.
__________________ The only thing that works on a RV is the owner...