Set it all the way back. It will feel more surfy and unstable at seed for sure, but much easier in the deep.
What angles you ride with? I trend to mellow out those too on pow days. I found that +18 + 9 works great to load your quad and calf without straining your back knee too much.
Ok, if I do set it allllll the way back I imagine I still try to maintain my normal stance width. I know that's a dumb question, but I asked it anyways. I usually ride 18, -6 I have never rode with a positive angle on my back foot before and it may be more change in setup than I can handle in one day. Thank you for the advice though.