This winter is bloody awful. It's very similar to that of 2013-14: mild, wet and windy, with gale after wretched gale, although until now (8th Feb) the gales have largely been to the north of the Purple Empire.
To date, hibernating Purple Emperor larvae have survived reasonably well in the wild. I haven't got many to follow this winter, but lost one in late November and a second in late January, both to assumed tit predation. (The second one may have moved, and not been relocated - but it was on a terminal bud, which is a suicidal position as foraging tits search there first and foremost).
Three larvae have moved after entering hibernation, two during mid-December and another in late January. Several moved whilst hibernating during the mild winter of 2013-14.
Here's No. 13, Wittgenstein, on the upper side of a fairly thick branch -
Here's No. 14, Kierkegaard, with unusual dark green and yellow mottling -
And here's No. 9, Heidegger, on an old stem scar -