I'd like to move beyond one-and-done. Due to hockey's randomness, a series would potentially yield a more worthy victor. The current schedule's off week makes it more possible, because you'd only need to add one more week of national postseason play, trimming the regular season by one weekend.
First round, week one, best of three at eight host sites (something like highest seed)
Second round, week two, best of three at four host sites.
Third round, week three, best of three at two host sites.
Fourth round, week four, championship, best of three at a national location, similar to the Frozen Four today.
It's a lot more hockey, but that's a feature.