Most of the Sierra storms have been fairly warm, so the difference between high and low elevation coverage and conditions is more extreme than normal this year. The best evidence of the rain vs. snow elevation issue is Squaw Valley's season snowfall of 155 inches at 8,200 ft. vs. only 61 at 6,200 ft. Lower snowfall is 39% of upper vs. normal of 60%. And Mammoth (239 inches) is ahead of everyone at Tahoe, also due to extra elevation/less rain and also not normal.
Based upon quality of ski terrain there is much more at North Shore than South, so in January/February I would normally advise advanced skiers to base there. But not this year. The rule of thumb is: stay over 8,000 feet. Mt. Rose is worth a look as it's high enough and the chutes are open.
You should watch weather closely. One big dump could get everything well covered, and if that happens you will want to hit Squaw/Alpine/Sugar Bowl.