I don't think you're too late.
I'd do exactly what you have planned so far except for the BFO. You can do that if you want, but I think BFO are really susceptable to early frost(someone correct me if I'm wrong). I would look at winter wheat or winter rye instead. Both will stay green even under the snow and will green back up early in the spring. Then next year you can till it back under as "green manure" and add organic matter to your clay. Then plant whatever you want next spring.
Brian