I would say it would go bad just after the point where it would only cause freezer burns.
Back in the day I used to keep a 6 pack or two under my truck seat. Freeze thaw Freeze thaw freeze thaw...........
That was some nasty tasting beer too!
If you cracked it open while partially frozen, you'd have to stick your mouth over the hole (don't get excited) to keep it from spouting all over the place.
Then the alcohol would separate from the ice---Yuck!
But hey---Beer's Beer ! Grin & drink it!
For you whipper snappers:
This was during the days when drinking & driving wasn't near as big a deal as it is now, because there wasn't more than two or three other people on the road.
And before you say the beer can would explode---They used to use heavy tin, not paper thin aluminum.