Does anyone have any experience with a subhirtella weeping cherry tree in zone 4?

I live in Minneapolis proper and have had the experience that the inner parts of a city tend to be a bit warmer than the surrounding areas. I am wondering if a weeping cherry will survive the winters in Zone 4. Minneapolis is smack dab in the zone 4 according to the maps, but I do believe that the cities offer more warmth in the winters. I have seen some search pages list the zones for the weeping cherry as 5-8 or 4b-8, but mainly it is a zone 5. I need help as I hate to plant something only just to kill it. Thanks!