2009 A6 Avant 3.0T, 180,000 miles but still runs great. It had sat in the cold for about 4 weeks in the cold (travel and then COVID) and when I went to start it the battery was near-dead and then flat out died. Put it on a trickle charger and 18 hours later it fired up like a champ! Took it to Autozone for an electrical test to see if the battery was OK. Test showed battery was fine but voltage regulator showed bad, putting out too much voltage. Drove it home (running fine) and shut it off, then remembered my radar detector has a voltmeter function. Fired it up, showed 11.8 on startup, then started gradually climbing (car stayed on idle) and was at 13.9 and still climbing when I shut it off. I'm assuming I'm looking at a new alternator/regulator.

My question- Autozone warned me that the overvoltage could fry my battery and damage other computers, electronics, etc. It's about a 30 minute drive to my shop, mostly highway. Is it likely to do damage in that much time? I'm trying to decide "pay for a tow" vs. possibly fried electronics PLUS tow". Any thoughts?
Dave