I think the crux of this dilemma is consideration for the neighbours. I can completely see it from the neighbour's point if view, and of course from the OP's need to get the boat washed down after a trip, engine flushed, etc.
I live a modern new-build housing estate. My neighbour's are nice enough but I know I'm the odd-ball in the street because there's a boat in the garage and I tend to work on cars on the drive most weekends.
Dont get me wrong, I'm not running Phil Mitchell's back street gaff, but I'm aware my neighbours roll their eyes when passing by. I remember working on the suspension on a car and it was a summer's evening. I was still outside at 10.00pm and it was still light enough to work. Up until this point I'd been hammering the hell out of a pinch bolt that wouldn't shift. To my credit, I drove out of the village to a layby to finish the job.
It's not essential to run the engine that night, it can wait, especially if your back late. Don't get me wrong, it's a complete pain in the butt, but accept that it can be seen as unreasonable. I'd also talk to your neighbours.