The Canucks are still winless (0-3) since head coach John Tortorella's return from a 15-day suspension. They've now lost six consecutive games for the first time in five years.
Vancouver, stuck on 63 points, is holding on to the last playoff spot in the Western Conference.
Pacioretty put Montreal on the board at 14:59 of the first period, deflecting home a P.K. Subban shot from the blue-line with his knee. Subban's first shot on the play was blocked by Canucks defenceman Jason Garrison, but his second found its way through traffic.
The Canadiens doubled their lead a minute later when White fired home his first of the season.
White couldn't have asked for an easier first goal, taking advantage of a sprawled-out Luongo, who thought he was covering the puck, to fire a backhand shot into the roof of the net and give the Habs a 2-0 lead. Dale Weise, in only his second game with Montreal, got an assist on the goal.
Former-Hab Higgins pulled one back for the visitors at 2:31 of the second period, beating Price on the power play with a redirected shot off his shin for his 16th goal of the year.
Montreal had killed off 28 straight penalties prior to Higgins' power-play goal.
Pacioretty was then awarded two penalty shots in a two-minute span in the second period, but failed to convert either of them, losing control of the puck on both occasions.
Despite missing both, Montreal's leading scorer became the first Canadien in team history to take two penalty shots in the same game — let alone the same period.
Pacioretty redeemed himself at the start of the third, though, beating Luongo glove-side after good work by David Desharnais to draw two Cancucks defencemen away from the crease.
The Canadiens added a fourth when defenceman Edler kicked the puck into his own net at 8:14. Plekanec, the last Montreal player to touch the puck, was credited with the goal.
Edler made up for the mistake at 12:21 of the final period, beating Price far side with a wrister while the Canucks played 5-on-4 hockey.
Pacioretty added an empty-netter for the hat trick.
Notes: Henrik Sedin (rib) and Dan Hamhuis (leg) were not in the lineup for the Canucks. The injury even forced Sedin to withdraw from the Olympic Games earlier in the day. … Weise and Raphael Diaz both faced their former teams after they were traded on Monday. … Travis Moen (lower body) did not dress for the Habs, and is listed as day-to-day. … This was the second of two games between Montreal and Vancouver this season. The Canadiens beat the Canucks 4-1 on Oct. 12, 2013.