Is this bluegrass and rye? My opinion, is after a few good frosts its time to shut down. Day temps in the 50's is barely warm enough. I find that grass does not do anything below 45 degrees. So 45 days and 29 degrees at night--not much will happen.
Remember that cold soil temperatures in spring will persist until about the first mowing. I wouldn't seed much before the first mowing. April 15 in my neighborhood.