Hi Lee,
I am not a corn farmer, growing wheat, canola and pulse crops in Saskatchewan but I am aware that every day that seeding is delayed beyond the optimal date range, the yield potential is lowered. This applies to all grains and doesn't matter where the location is. In our area and 100% of the Canadian prairies the seeding delay is already at least 10 days and getting worse every week. Many areas on the east side won't likely seed at all as there is just too much water that won't drain away.