Xinjiang Fragrant Pears from Seed

So about 3 years ago I bought some fragrant pears from the store and I stated the seeds. I had a total of 8 that worked out. Over the next couple of years I had a few ended up losing. So I am now down to 5 total plants. So this year I am expecting that these plants hopefully will flower for me and I can get fruit. I am in Calgary, Alberta zone 3 to 4a.
Any advice from anyone what I should do to get these to flower? It appears to be a bit cold here for them as each year they seem to get a little frost bitten on the tips.

Any other advice on what I might do in the winter so that I can get them to grow a little taller?



Can i recommend a dug in greenhouse or a sunroom to you? Maybe not helpful but they are in pots