Hey, Love Coral Pink Utah...
Late October to mid March is too cold depending on the weather/snow (6000). So we ride at Coral from April to Early October and skip July, too hot during the day. Even during the 100+ days at Coral it still drops under 60 F. at night. No AC or heat needed usally to sleep.
During the cold months at Coral we ride at Dumont Dunes in CA. since the season there starts Halloween and runs 'till about Spring Break. Summer temps at Dumont are 125+ July/August sometimes (Death Valley).
Warning on the route to Coral. If you use MapQuest it will probably tell you to go through ZION National Park in Utah.
Avoid that since there is a tunnel that goes through the mountain and if you have an RV/trailer they have to shut it down and pilot you through (a fee applys to entrance and pilot sometimes). Route is a little shorter on mileage but WAY longer in time since there is the tunnel delay, tourists, and switchbacks.
Anyways, water is available in Kanab (where the preferred route takes you through) at gas stations. There is a Sinclair right as you get into town on the East side of the road before the first traffic light. $2 water and $2 dump, if they even charge you. If its closed at night or Sunday the water and dump is still available. Sometimes I stick $5 through the front door mail slot if they aren't open.
Here is a link to my family website about Coral Pink.
Sly4Family.comSly