Preparing annual raised bed for overwintering in zone 3-4 long cold winters?

The temperature is dropping, the days are shortening, and we've even seen our first frost here in North Eastern Ontario, so I'm starting to think about winter. We have a few raised beds with annual vegetables which won't be planted again until the end of May or early June next year, about 8 months from now. I'm wondering if there is a preferred method to prepare the beds for wintering. This is a zone 3-4 area, with winter temperatures sometimes getting as low as -40. We've got some cabbage, broccoli, tomatoes, chard, kales, some cucumbers and zucchini regular annual market garden vegetables.

Chop and drop everything? Chop and drop everything, but remove things that can get blight like tomatoes and zucchini? Chop and drop and mulch? Just mulch? or am I overthinking things as per usual and just leave everything to finish going to seed and rot until next year?

Cheers,

Rob

There are a couple of benefits to leaving things be that I can think of from the top of my head.
1) Shelter and food for over wintering insects and birds.
2) Easier to clean up in the spring after a winter beating.