I would avoid rotavation like the plague while you have all those weeds. As you say, it would chop all the roots up into lots of new plants.
I always advise new tenants to get digging before the end of the year, because on our site the soil gets quite sticky and soggy in the new year. If the soil is sticking to your boots, keep off it. If the soil is sticking to all the weed roots and you can't shake it off, I might also delay weeding until the soil dries out a little.
Don't forget you can cover too. I always advise that you should have dealt with, or covered, or have a plan to stop growth on, perennial weeds before they start active growth in the spring.