With Bowl games going on, you might want to consider taking it to the parking lot there.
I agree, also, other large athletic events, RV clubs (yes, they exist), AARP mag, AAA Travel and Leisure mag, advertise at retirement resorts, advert at large church bulletin boards, work bulletin board... I would do an internet search on RV to find RV clubs. Or how about trying to sell through an RV dealer? - Even if you lose money, at least you would get it sold. You could enhance it some way, perhaps, to increase the value...