well as you cannot ride cotton wood pass on your rzr,
you could park at the trading post taylor park,
just tell the people in the store what you are doing i don,t see them having a problem,
its all safe around there,
Chris (Bloody Bill) is right, you cannot ride over Cottonwood via ATV or even on Cottonwood Pass anywhere. Your better off staying in the Taylor Valley. You cant park at the Trading post long term, but there is Camping spots all along the Taylor Valley right off Taylor Road.(the dirt road running north from cottonwoof pass by the lake) And the road to Tincup (dirt) from the trading post going South. There is a 14 day camping limit in the area and Yes your truck will be fine.
It is a 1 1/2 hr drive from Buenna Vista to the Trading Post at Taylor Lake. I dont think you want to drive that everyday. IF the trading post is closed for some reason, Almont Co is just 25min or so south on the Blacktop road from the lake. Gunnison is another 20 min from there again south. They are doing construction on this road and you could have a 20 min delay for traffic. This is in case you want a Hotel or supplies that are closer than Buenna Vista.