Hi CVers, I'm approaching the 1 year mark of my first vintage bike purchase (what a ride it's been!) When I bought it I stripped down everything and did a complete overhaul, and now after a season +winter commuting I believe its time to do it again, or is it?

At the very least I want to re-grease the BB and headset, and take off most parts to clean and put a coat of wax on the frame. I might spray some frame saver in as I didn't do that the first time and have been riding on salty midwest roads.

How often do you perform major maintenance tasks on your vintage rides, and how do they differ from the maintenance needs of a more current bike?

So much depends on how and where the bike is ridden, I don’t know that an average interval is a meaningful metric. Given your description, a full annual overhaul seems appropriate.
Wheel bearings probably take the worst beating. Do you have fenders? If not, your headset will also be fed a steady diet of nasty slop. Those could probably do with more than once per year, depending on mileage.
Better too often than not often enough.

Really depends on a lot of things-- how much do you ride in wet snow / slush / salt? IME that's the worst possible condition for wear and tear on a bike, next to riding on wet sand. Or do you just ride on mostly cold but dry days? The bike I ride all through winter weather gets a new chain because the salt really corrodes them quickly. I don't service the hubs or headset or bottom bracket as they're mostly sealed. I just go over the bike on the first warm day each spring and assess. But the chain is a given. Then maybe every other year a new cassette. I try to use high quality cable ferules with o-ring seals so water doesn't get into the housing. They eventually fail, and once I start getting cable freeze-up, I know it's time for new cables + housing once the spring thaw comes around. That happens about once every 3-5 years.

If you're using older style systems that aren't sealed, I'd consider either a very careful assessment or outright rebuild each spring. This is why for my winter commuter I just go with modern sealed components, the maintenance-free nature is a real plus!

+1 to fenders, those will greatly prolong the life of your bike.