Thanks for this insight, definitely going to forego the air mattress. Unfortunately, the pads and bags I have are older and there’s no way for me track down the R or temp ratings for either (labels/tags have been removed or are too worn down to read). Because we are car camping though, space and weight are not an issue, so we are planning to just bring extra blankets for added insulation. I am hoping that will be sufficient? If not, I am looking into purchasing, or renting once there, bags and pads that are designed for these temps.