Good dark grape for z5

I’m tired of trying to find the secret peach that will bear fruit here. I’m running to daylight: Grapes work.

Any suggestions for a dark colored grape for z5 (rocky mountain foothills)? I understand Concord can’t fit in the season. We like ‘Glenora’ a lot but I would like to try something different. We already have a baby ‘Himrod’ grape, and wife likes darker grapes.

If you like Concord grapes, Van Buren is similar but 3-4 weeks earlier. I had a few bunches off of a 1 year old vine last year and they were very good, barely a smidgen under Concord for flavor. Like Concord, they are seeded and slip skin. I got mine from Schlabach’s in NY but I think Rolling River Nursery sells them online. Rolling River lists it as a zone 7 but Double A Vineyards and Iowa State U have it hardy to -20. We hit -20 this year and were below -15 a few additional times. The one I have died back, but is growing back from the ground nicely. Early Cambell and Price sound like other good Concord-types for shorter seasons, but I haven’t tried them first hand (Raintree Nursery has them).