Aside from the "take the dog" and other wisdom (which for some people is excellent advice), I always say - focus on destinations and make camping just a means to an end. Since you are in TX, you have plenty of options (many of which you may already have gotten your fill of) but a nice trip to Austin and doing some people watching and margarita drinking followed by a siesta in the camper sounds fun. Work up to it and from it. 250 to 300 mile days tops. Talk to the DW about what her top 2 or 3 destinations would be - pick the one that is most approachable and plan an adventure. Include a day at the spa for her if you need to.
Another suggestion - make the next trip a hotel trip. Let her be reminded of the cost, relative inconvenience in some ways, and the fun of calling your own shots.