I also live in the north and just minutes ago had a paving company come over and give me a quote on extending our driveway. He gave us a pamphlet and also answered all our questions including when to seal. He recommended at least 90 days after new pavement is installed unless you have had extreme hot weather. He also recommends a latex base slurry/sand mix industrial sealer which will extend the life expectancy by about 30 %. Hope this helps.