I'll say no. The odds of any one quarterback in the NFL winning a championship in the remainder of their career can't be better than 50/50. Much more so for a guy who will be 37 next year.
But beyond just playing the odds, I'll also say no. The Pats don't have a full squad that's good enough to win right now. They certainly could get back there, they've been right there the last two seasons with teams that frankly weren't that good. If Gronk is healthy, and the same impact, that makes them an elite offense even if all they have is him and Brady. But the defense hasn't been strong either.
One advantage is Brady's cap number will continue to be relatively low, between $13-15M, each year. So his contract isn't much of a burden at all. They just need to find some playmakers defensively.