If you survived that record breaking cold in Texas, yes your batteries took a beating.
To be sure you can take them into any auto parts store and have them tested.
I also installed a DC-DC charger. My write up here.
https://www.montanaowners.com/forums...hlight=charger
In March we spent 10 days dry camping on Ocracoke Island OBX NC Campground.
The solar panels worked great again as they had previously, however, the last three days we had nothing but rain. We used the DC-DC charger in the morning and again in the evening to recharge the batteries to get us through those three rainy days.
Next year we plan on going west and doing a lot of boondocking on BLM Land. We will be taking our generator with us on that trip.