Montreal's defense did a great job with their bodies, wingspan, stick work to "traffic control" the offensive chances of Toronto, Winnipeg, Vegas and Price was always there to make the save. I feel like they were effective keeping the offensive cycles pinned to the perimeter, or else shunting offensive chances to shots along the side wall, or laying such a beating on players that by the time they got to a decent chance in the slot the opportunities were rushed or body positioning of the shooter was thrown off.
Long story short, they played a great team game and Price was the most important component, gaining more confidence as the playoffs went on. I'm not really sure why Price needs to be elevated beyond that. He was quite beatable in the early part of the series when the Leafs went up 3-1, and he blew a 3-0 and 2-0 lead in successive games.