Hi Rob,
Glad you posted your questions here. I hope you aren't too alarmed by the responses. But Mt Whitney IS a beast in winter. I think with your experience level, going with a guide service would be a good idea, and much better ensure you have a safe trip. Bob West mentioned several, and Kurt Wedberg's SMI is world class.
Here is a post written originally in 2005 by Whitney veteran, SAR member and Volunteer Ranger Bob R:
So, you want to climb the Mountaineer's Route in winter?Last year was a drought year, so people were hiking the main trail all year long. But the year before, waist-deep drifts made the main trail impassable. It all depends on what the weather brings. Most winter ascents of Mt Whitney are late winter or early spring, once the snow consolidates so sinking in is not such a problem, and there are fewer storms.
And one more thread to read:
SAR on the MR: 2/25/12
