Hi Jason,

I am just south of the border in North Dakota and I have been using rye for a cover crop before soybeans. I do not know how it would work for veggies that you grow. Here are the trials in Langdon, ND, which is very close to the coldest spot in the States. NDSU has one variety that is relatively quick to head in the spring.

https://www.ag.ndsu.edu/varietytrials/langdon-rec/2020-trial-results/LRYE2020.pdf/view