Just as a test… why not do a force charge to 100% to get some heat into the battries ?
Start it at about 7pm at night to try and keep it cheap - but let it get to 100% and then do a discharge.
I use “Predbat” and that gives me the option to do a Forced SOC - it’s worth giving it a try.
or - I keep my batteries warm using heaters… : Battery SOC calibration cold temperatures - GivEnergy Products / GivEnergy Batteries - GivEnergy Community Forum