On my Arizona trip we first drove West via i-90, leaving mass March 21st. We saw some downright chilly weather along the way. Low's in the single digits at night. back in December 2022, I'd gotten these 12volt Facon pipe elbow heating pads and with some foamboard/reflectic, they worked great for keeping my water jugs from freezing, and keeping my batteries happy. I remember we drove to Albany when there was a cold snap. When I started the drive the batteries were only like 5F, and the heat pads got them up to 30F in no time so they could start charging, like maybe 1 hour. Very happy with that.