White clover - How late to plant and how long is seed viable


Two part question. Im in North Central VT, zone 4, Ive always planted my fall clover with a cover crop in mid August. This year between drought conditions and swarm of turkeys, my first shot at fall plots were a total, 100% failure. I was trying the no till method and the turkeys didnt stop until they had uncovered it all. Sept 1 I ended up using my ATV disc and did some quick annual rye which is now starting to make my plots actually look green. I didnt dare do clover so late, now Im kind of wishing I had.

So, how late is it safe to put down clover seed before true cold/snow arrives? And second part of the question, say I wait until alot later, like just before our ground is white, and put down seed, will it stay viable there until spring or should I just wait and seed it after snow melt at this point?
Broadcast RC now and it will do decent. Wait with WC and frost seed March-April. Good luck.