I live fulltime in a 40 foot fifthwheel! It is so nice to 'meet' a fellow RVer here!
I am not sure how big your workout space is, but you probably don't have opposing slides since you are in a motorhome. My workout area is about 5 by 7 - basically the kitchen area. This area is part tile and part carpet, which is one thing I don't like about it. But, it's still bigger than our first RV
I find the Firm tapes to be ideal for RVing. Most of them use a small area, and you get a fantastic workout with just the dumbbells and steps. In fact, they are coming out with a new step that adjusts to different heights so you can use it for all the tapes (previously one needed at least two different heights). This is a small step, about 14 inches by 14 inches, not a big step like most videos use. I don't have room for one of those, but the little one isn't so bad, and could make a handy step stool if you have those hard to reach cabinets like I do! Step is a good way to increase the intensity without going high impact or using a lot of space, and Firm step is pretty straightforward. I started out with the Firm Basics (beginner tapes), and now do Vol. 2 Low Impact Aerobics (which is actually a total body strength workout and cardio workout in one - some high impact though, but I modify) and Time Crunch Workout, Not So Tough Aerobics, etc. Their new workouts look great and I can't wait to get them!
My other favorite is Charlene Prickett videos. Her low impact floor aerobic videos are very good workouts but don't take up much floorspace. I have to do very little modifying with her. My favorites of hers are Low Impact, High Intensity, More Muscle Less Fat, Start Your Engines, and the low impact 3-pak from her TV show, It Figures. All of these except Start Your Engines have fabulous mountain scenery in the background, which I really enjoy!
I tried Gilad and his workouts are good for small spaces too, though there was a bit too much high impact for me. Kathy Smith's Peak Fat Burning is a short but fairly intense interval style workout that doesn't take a lot of space. I have heard that Urban Tai Chi is another good one, but I haven't tried it yet.
I hope this helps. I look forward to reading your posts
Shelley