Very cool !
My band got together about 20 years ago with those same goals in mind about playing out just a few times a year.

We've pretty much stuck to that and it works out well when you have a family and other responsibilities.

Still playing with 2 of the 3 guys I started with (we seem to have musical bass player though)

We practice maybe twice a month for about 3 to 4 hours.
And what has really help us over the years has been coming to practice prepared. When we all do that we can add up to 3 new songs every time.

Good luck and have fun!!