That's very interesting! I don't have any suggestions (and no longer live in MN). I'm on the Keweenaw Peninsula on the Michigan U.P. and our climate is a little more moderate. We planted two quince bushes this past spring and they seem to be doing well so far. I'd have to look at the tags though, to be able to tell you varieties, and of course have no history to go on yet and again, the slightly different climate. I'll be watching this thread with interest though!

There are at least 3 varieties of hardy quince growing and thriving at the Minnesota landscape arboretum in Chaska Mn (zone4b). I checked them out in October 2018 - but didnt write down their names. Might be worth a visit. They have a plant finder button so you can find their exact location and maybe their names, but it is nice to see their shapes/fruit/coloring in person.