The road to pole creek is not plowed. Most people just wait till it melts out, which will not happen for a while. With the recent warming I would imagine it is close maybe 5-3 miles from the snow line to the TH.
jefferson is the same story. There is winter approach for Jeff. At the big bend in the road head to jeff park. I have personally not done this but it is the standard winter approach. Have no idea how far you will have to park your car from the big bend ring now.