This was actually a real possibility for me a few years ago after a false positive for a certain liver disease.
Flanders Red has come up as a possibility along with a few other hefty OG beers that would need time.
I also considered some low ABV beers that would be ready in 2 months tops and would be awesome.
From experience, before I was tested a few more times and learned that the positive was in fact a false, I brewed all sorts of stuff and told SWMBO "If this is it, thats fine, but I'm brewing til I know!"
You probably wont ever have "one last batch". As homebrewers having SWMBOs who are fully used to our hobby, they'll probably realize when the time comes that there is no "last brew". There is just brewing until we know.
