When using lemmy in the browser, there are some userscripts that do this.
https://greasyfork.org/en/scripts/469273-lemmy-universal-link-switcher

but I would love to see this as sort of default behavior, so that the user indeed does not have to “fight” the system to get it to subscribe properly.

Yeah, I would discuss this with your wife. But it seems you have good reasons to stick to your schedule as much as possible. See where you can compromise to have an evening with the in-laws or something but this should be very manageable if properly agreed with your wife.

Bullet 2 rules out libertarian.