Flippin' heck, I hope your hubby is okay now. It's been really cold today here in the normally balmy (ha!) south west, so that can't have been much fun for him. And if the Highways Agency have given him help, on a Friday night on the M5, that means he really has been there longer than you'd expect, even as a lone male driver.
I don't drive much now at all since I mainly work from home, but other household member does, and we always try to make sure we've got one of those little tin foil blankets in the glove box just in case, as well as a bottle of water at least, and while other household members may laugh at me I always like to make sure we've got some crackers and a flask of hot water and coffee with us as well, especially this time of year. And lots of fleece jackets and spare socks and things. And if we're visiting family up north even more things get added. My family still laugh at me for insisting we have a bit of old carpet and a snow shovel and a reflective waistcoat or two various other bits and pieces just in case. They never argue with the chocolate rations though, strangely enough...
And yes, if the recovery service he's with won't do an upgrade, definitely change recovery service.
And ignore all the silly people on here who are obviously so perfect that of course it would never happen to them. My last car lost power on the M5 in the middle lane once for no apparent reason; it's not the nicest place in the world to get stuck! (Traffic was mega busy and it did come on again a few seconds later and then was fine, but all my nine lives flashed before my eyes that night!)
And yes, people were right to point out Avonmouth is actually the closest railway station to Gordano, though in some ways Taunton might have been the better bet as Avonmouth is a bit out of the way still. But anyway, it sounds as if hopefully he's on his way back to you all now. And just think what a story it will make when he's all nice and safe and warm back at home.
I take your point about him being from the north as well - most of the time there's a 5 degree difference between say, Newcastle and Bristol, but it's really chilly at the moment. [Remembers northern parents muttering, "Make sure you take a coat" when I went out. Not that they needed to worry. I always looked like a small plump Eskimo. Even in the summer. Still do, from some angles....]
Seriously, get the wine ready for when he's back with you.