Sequoia would be accessible from the south entrance, on 198 from Visalia into Three Rivers.
The drive up from the foothills to Giant Forest (~6400') and Lodgepole (~6700') is quite scenic, but there are often chain controls at the higher elevations after storms and there will be a lot of snow around. Here's a webcam from Giant Forest -
http://www.nature.nps.gov/air/WebCams/p ... ekicam.cfm
Check out the winter edition of the park newspaper -
http://www.nps.gov/seki/parknews/newspaper.htm
It is still winter in the high country and to get anywhere away from the car you will need snowshoes or skis.