If it's just one or two trees, it is possible to plant them in the sheltered area, and in the month or so when they are coming out of dormancy, and at risk from a late frost, to throw a big tarp or piece of construction plastic over them on the few nights where it's going to frost.
How bad do want to be the only guy in your county that gets fresh
local, beyond organic almonds???
I like fresh figs, and I live in zone 5 michigan. So I grow them in pots, and then they go out to the
greenhouse about a month before the last frost. They like a long season to get the figs ripe.
After they go dormant in the fall and they have a couple light freezes and lose their leaves, I haul them down in the cold basement until spring.
You can grow peaches (and almonds are really just specialized peach trees) in containers too.
How much work do you want to go through?
Permaculture is a design science. It's all about problem solving while looking at the whole system, not just the immediate problem.
Really defining the problem is at least half of the battle.
If you define the problem as, "How do I grow almonds in zone 4, no matter what?" That will lead you to some techniques and tricks to get almonds in zone 4.
If you define the problem as, "I would really like some nuts that aren't shipped from california and treated with who knows what. What nuts grow around here that love my climate, ie, will need little if any extra work?"
Ahhhh, that's a very different problem to solve. Hickories grow great here. So do walnuts. Hazelnut bushes may give you a yield by the 3rd year, IF you get a variety that is resistant to the eastern filbert blight, which is endemic in my part of the country. There are northern pecans that taste fantastic, but are about half the size of the southern papershell variety. But they may take 7-12 years to yield.