Interesting research by Dr. Einhorn which regarded "Regina" cherry as more flower bud hardy to critically low temperatures. These were carried out for different days of winter and comparing results to others such as Bing are found on 20th page of 33:
einhorn_to_freeze_or_not_to_freeze.pdf

One place earlier in the file lists Regina weeks later in bloom timing when comparing to an average blooming Bing. Regina is also known as non self fruitful. To have this going for you (Konrad and company) around Edmonton you might think of bloom overlapping to another hardy cherry type such as evans, romance series, or other, as these are known to be pollinators for sweet cherry and closely related enough.

From those it's possible to grow second generation trees as non-fruiting flowering "wilds" as would happen in an orchard by bees, then birds to the outskirts of an orchard. They grow as hybrids and due to the nature of the cross and of chromosome counts have never (rare cases possible) ever been found to fruit.