Why do you have to wait until spring? Is your ground frozen solid?
If you check the map
here at the USDA page, you'll see that the range goes right up into Canadian provinces that have permafrost in them. So putting them out in frozen ground isn't going to kill them.
I would say you have two choices: (1) start them in a pot in a warm place and then transplant them outside when the weather warms up, that way they will have a head start, or (2) leave them outside under some mulch until you can work the ground and then plant them. From my
experience, they seem to re-emerge early in the spring, a few weeks before corn planting weather.