Well, I'm still open to suggestions...
You guys were correct, my son could sponsor us -- but there aren't any vacancies at the main campground when we're going to be there. They have a secondary campground, "Range 14," but it sounds pretty barren in the on-line reviews - only 20A electric and water, no sewers or bathhouse, just a porta-potty. I really don't think SWMBO will go for that one.
Thanks for the info, Coyote, I'll check out your suggestions.
'94 Holiday Rambler Navigator
38', Cummins 8.3 300hp, Allison 3060
pushed by a 2005 Honda Element