I would reiterate what stbrnnr said about Sky High – with the North/East exposure it will take the longest to clear of icy conditions. You should also be aware of the recent rescue from that trail – see the Nixle report at this link: http://nixle.us/BLK4Q
Short synopsis is a fully equipped and experience hiker went up there with crampons and ice axe and in spite of the gear he slid on the ice. Luckily he know how to use the axe and arrested his slide, but injured himself in the process and had to call for rescue on the PLB he was carrying. Extra tip, if you activate a PLB you probably should not go wandering away from the spot – the helicopter went to his location and he tried walking out, but thy were able to see his tracks and found him at Dry Lake.
Also, you mentioned Fish Creek – are you aware that the road into that trailhead is under winter closure until early May? Are you planning to walk in from highway 38? If so, best of luck! Personally I’d recommend the South Fork trail instead. You can get to Fish Creek Saddle above the Dry Lake area if you wish, but South Fork is more accessible right now.
The guy that went into Vivian Creek on the 8th posted his You Tube video on the So Cal Hikers Facebook group. Try going to this link and find his video: https://www.youtube.com/channel/UC34MVsreWXxyh3seQRsuKCg/videos or search You Tube for “Norwegian Xplorer” to find his videos. He shows the ice on the road leading into where you would normally park and great coverage of the trail conditions all the way to the summit. Looks really gnarly above High Creek but there was at least one spot up there that was completely clear of ice and snow (probably not far enough to take off the crampons, though.)
Hope that helps!
Any other questions, call us at Mill Creek.