If you have 2 feet of snow outside and only a hoop house - even if it's been there since autumn it may not have enough air volume to hold the heat high enough to let your seeds germinate. They'll either sit dormant until the days warm more, or quietly rot away.

Can you start them inside in a warm space then thin and transplant into individual pots when they're about 2" high, before you harden them off under the hoops and plant out in April?