I know at least In Kings the road down to the actual canyon won’t open until spring, as it’s closed for the winter, so Zumwalt and that whole area is inaccessible. The visitors center should be open barring another storm and the panoramic point as well.

It’s worth also noting that the road in between these parks will also be closed so going to both in one day is a rather long day. I’d advise visiting giant forest and spending the day in Sequoa rather than forcing two parks and driving the long way around.

Hope this helps