Minimal maintenance to keep cold-weather slush/salt problems at bay?

For a long time I've had a series of winter beaters that I ride into the ground. Until I acquire my next beater, I'm currently commuting on an older bike that I've owned for almost 40 years -- bought as a teen in 1986. It's past the point of keeping pristine, but still, this one I don't want to ride into the ground, I have a lot of history with it!

Just curious what minimum maintenance you would do in the following situation:

--bike is an 80's tourer

--stored overnight in heated garage, also kept indoors during the day at my workplace, rarely left outside more than an hour or two

--drive train is 3x7, canti brakes, not a great deal of choice for tires as the wheels are 27"s

--live in Montreal, where we have good infrastructure (for North America), but crappy weather conditions in the winter. There's a lot of slush that builds up, and there's a lot of salt in that slush. I don't ride if the bike lane conditions are icy, as I don't bother with studded tires.

Currently I'm hosing the slush off in the garage of my building when I get home in the evening, and putting wet-weather lube on the chain in the morning. (It's a shared garage and I can't have a stand there, and hot water/bucket would be a headache but not impossible.) What else would you do, or what would you do differently?