Same here disconnect battery and reconnect every 2 weeks and give her a run around yard until warmed up. HAve charger if slow to start sometimes.Disconnect the negative on both mine while off the road for few months for last few years..reconnect about every 2 month start let run come up to temp move it about.
No issues
Worst that will happen is cold might kill battery if if weak
A dehumidifier is a good long term investment. I keep one going in corner of garage over winter months even though garage is dry. I put it in cars for a few hours from time to time during long damp days and keeps seats,carpets nice and dry and mould free.I got a few Dehumidifier/Reusable Car Silica Gel Moisture Absorber Bags of amazon i keep them under front seats & 1 in boot and one hanging off mirror.
Worth looking into