Inland PNW has a a couple of more that might work well for you.
First one is a little more upscale, but just suffer. Silver Mountain in Kellogg, ID is perhaps the easiest access ski area that really gets snow. Kellogg is an old mining town that is still trying to reinvent itself as something else. Short lines especially on a weekday. Fairly cheap tickets. I had a season pass here for a couple of seasons. Good terrain.
49* North (Chewellah, WA) has their RV spaces is cheap and not very many people go there. Really easy access with an RV. The town even has a really funky little indian casino, so cheap food. Outstanding low angle tree skiing and a lot of acreage to explore. If you get in a line it means the lift was stopped. It plays well with Red Mountain and Whitewater they are all within two hours. There are some good skiers their but you will rarely see them cause they are out playing in the trees. Hit 49 on a Friday if you can, they are closed Wednesday and Thursday it it has been snowing you'll be laying down fresh tracks pretty much all day. This is my home mountain so on 2nd thought, you won't like it.
Go South. Soldier Mountain outside of Fairfield, ID. Only 2 old chairs about 1,500 vert. Easy drive with your RV. About $30 lift tickets, and $200 will buy you an all day seat of cat skiing, What looks like very easy to get at side country too included with your lift ticket. I have only skied there 1 day a Sunday, skied first tracks at 3 PM on a Sunday, so crowds are not an issue. This is the kind of place you might end up making turns with the owner (I did). This place is a hidden gem even from the dirtbags; it is way off the radar (they might not even have radar there). Fairfield looks like Steamboat probably did in the early 60's, I'm going back.