Hey Folks, Kids (5 & 7) have a 4 day weekend so we're going to escape to Great Sand Dunes NP this weekend. However, I noticed the overnight temps are about 15 degrees. I'm only coming into the end of my first year with the Santa Fe, so I've never been in temps like this with the camper. Does the onboard heater do an OK job keeping the camper comfortable in those temps? Anyone have experience with this? Thanks!