With chains in any situation you want a tight fit - tight as possible. Anything else will lead to the chains moving, slipping, wearing early, and coming off, which if it just means losing a chain is fine, but if it comes off on the inside, you will damage stuff like brake lines or anything else in the way.
So when considering chains on an expensive RV with fragile body work and close tolerances and duals, you need to be very picky about what you use. Any over the counter chains will require adjustment and most are cheap imported junk meant for light, occasional use, with a ”no returns” customer satisfaction policy.
The only chains I would put on my RV would be custom fitted and/or custom built (by me) with good quality materials sourced from a good chain shop. And you only need to chain up the outside rear tires - dual chains are a low speed off road work truck thing. Yes they maximize traction, but all you are doing (hopefully) is driving on paved roads with a few inches of snow safely as possible, and/or satisfying chain control.
So you could buy truck chains for your tire size and custom fit them to be really tight (put them on drive for 1/8 mile or so and readjust) or measure and buy side chain and cross chains and make your own. Whatever you do, don’t buy inexpensive or light duty chain(s), and drive slow when they are on. Theres too much at stake for chain failures on an RV.
I lived in snow country for over 20 years (4200’ in the Sierras) at the end of a 2 mile dirt road that I had to plow myself with very little help from neighbors, and I went through a lot of chains. I usually just went out on I-80 at the beginning of a new storm and collected a half dozen new chains that fell off big rigs (because they didn't fit or were installed wrong), and cut them down to fit my plow truck tires. But if I were buying new for an RV, I would only use Pewag chain made in Colorado from US steel. Either from the materials I noted above or for your tire size and then custom fitted. They should fit tight enough to not need rubber tensioners to take up slack. Use the fold over side chain fasteners along with 3 or 4 cam-type adjusters (see pics).
The other option, if clearance is more of an issue, would be tight fitting cable chains if you can get them for your size wheels/tires (19.5?). They don’t offer as much traction, but they fit in tight locations and will get you passed chain control. Just don’t expect too much from them and like chains, make sure they fit tight, re-adjust after driving a short distance, go slow, and try not to spin your wheels. You do not want this stuff coming loose while driving.
That’s about it for chains. I’m glad I dont live in snow country anymore and I‘m not interesting in driving a RV in the stuff. I’ve done it several times and have never enjoyed the experience.