I rarely run my tow car, Disco, through the winter months, its owned for towing. Its not the ideal car for use as our "shopping trolly", nor our most fuel efficient.
I leave it for long periods with a CTEK charger plugged into the rear towing 13 pin socket, via a homemade, special purpose lead using their plug and socket system.
This set up being way more convenient in my case than directly onto the battery, or under bonnet as the vehicles front end is a tight and dead end fit in the garage.
This the same as I did for years with Defenders where the battery under the seat was even less accessible.
{CTEK, rather than my Aldi/Lidl semi clones as we have overhead cabling with more than our share of power outages]