I've mused about doing this exact same thing for awhile now. All of the changes to zeds, A.I., and such over the last few alphas have really left me with this desire to not keep repeating the same cycle over and over. As such, in my last A18 run, I just abandoned building any sort of horde base. Instead I find a sturdy POI that I can make a few adjustments in a quick amount of time to serve as the horde defense base of the week. We still spray bullets like they are going out of style but we don't have to repair the damage and can be free of burden for the next 7 days till the process repeats. Next 7 days, find a new POI!
Granted, there is usually a day devoted to restocking lead, nitrate, and coal so we have 3k+ ammo each to fully expend on a horde night. Brass is an ongoing search as every radiator, brass lamp, and car is wrenched till we have to feed dukes into the forge.
Also, I don't build bases anymore. I just take over interesting POI's and bend them to my will over time. They only have a single purpose and that is to be a place to keep my stuff.
To be clear, horde nights are still one of the more fun aspects of the game for me as it is a pure shooting gallery (who doesn't love shooting zombies?) so I'm willing to put in the work to have bullets. I'm just not into the MASSIVE amount of base repair and time it currently requires. Also, I don't like cheesy tactics like OP presented, jump bases, or stuff of that nature.