Reading that white paper, it indicates that it is
root zone temperature which will affect bud break and bloom the most. That means the snow pile method would work on the root zone and not just up against the trunk. If you get snow, you probably want to insulate it from the weather to reduce it's melt rate. The best method I can think of to do that is to just use a good covering of
straw or sawdust, like they used to do in the old ice houses to keep ice through the summer. Admittedly they started with ice, but I'm figuring that would translate to snow fairly well. I'm going to try that with my little orchard and see what we get. I have a couple of trees that are the same as the ones nearby, one gets a good straw covering and the other just gets the usual.