Tom,
You had said earlier you were going to operate 1A for field day. If I'm
reading the rules correctly (not a given), looks like class A is for
portable club or non-club, 3 or more persons. Looks like class B is 1
or 2 person portable.
You might want to peek at the rules at the ARRL sight, but I doubt if
the FD police will kick in your RV's door, no matter what class you select.
Good luck, have fun, Steve KW3A