if avy gets rated in extreme, you need to make a honest assement of your plans.
Not just the ravines can slide on that peak. Some of them snowfeilds on the cone are easily 25-30 degrees. they might slide once a year and it maybe be after this big snow this year. \\not saying don't try it, just talk to rangers, they will be around this weekend, or swing by the harvard cabin and ask questions. it may blow off the cone and it may not.
just b/c its the winter route that avoids most avy paths doesn't mean its immune from sliding, its steep, and can load.
hope this helps. just my 2 cents on the matter.