^ Although not the OP's question, I would consider an enclosed trailer as well, if you are putting any real miles on the trailer traveling with the RV, for a couple reasons.
With an ATV comes extras, gear, gas cans, spare tire, etc and having the security and extra storage of an enclosed trailer is very welcome for not only the atv stuff, but the rest of the rving "stuff".
Also, if traveling in inclement weather, the machine isn't getting soaked and covered with road grime. Yes you can buy a good trailer-able cover for a couple hundred bucks, but it'll also require replacement every couple/few years due to wind/sun damage if it sits outside.
Plus if you buy it right (like most any utility/cargo trailer), they retain their value quite well, which helps take the sting out of the extra cost of a cargo trailer.
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold