As you've no doubt gathered from the above posts, clothing you take along depends on what you think you need for the trip, AND on how much storage space you have on your specific rig -- it's a tradeoff with everything else, too. But, as Gary says, RVers tend to be rather casual, rarely dressing up. Even in our 38' DP, we didn't carry suits or her equivalent, just jeans and nice slacks, with shirts to match, plus enough underclothes to make it between washing sessions, which were every few days with the on-board washer and dryer (stacked) that we had.
In the Trailmanor TT, which was our first RV, we took a lot less, and took mostly shorter trips, but were dependent on campground washing machines on longer trips. But we also had relatively little on-board storage, too, though we had some room in the pickup we towed with.
So it all boils down to a careful balance of your personal needs and the storage space available, along with what other things might be needed for the trip.
No two folks/couples will come up with the same answers, though (even with identical rigs), so you need to carefully evaluate your needs.
