Do you have a pair of calipers that you can use to measure print height? If yes, don’t take it off the bed. Measure the height of the print, delete those layers out of the gcode (it’s just a text document after all), and reset. Note that the gcode and printer setup might require some fiddling to get right, but I’ve resumed prints like this without problems before. They don’t all look perfect at this layer, but they’re certain better than nothing. Once the print loses its hold on the bed, all bets are off.
Agree that the result won’t be a perfect print, but I personally prefer this route over printing the other half, sanding the first half flat to account for a partial layer like you said, and then gluing.
I guess it comes down to what you goal is. 90% of my prints are functional and I don’t really care if they’re a bit ugly at times.