I always thought you dig ground over especialy heavy ground and the frost will break the soil down for you making it easier to dig over in spring.
But digging now you bring up weed seedling for the frost to kill off I like this idea getting the weather to help you.
If you dig your ground and then put manure on top the frost should break down the manure lump and the following rain washes the goodness into the dug earth. Just some ideas I have heard sounds good.
