You don't actually need to have a goalie on the bench. I found this out last year when UNH played at Yale. The #1 goalie to start the year was Ava Boutilier but she got injured in early November and ended up getting a redshirt season. The #2 goalie Kyra Smith was the starting goalie for the game against Yale. Not sure why, but the #3 goalie, AJ Pelletier, was not able to make that game. The starting Right Winger, Meghara McManus, was the backup goalie. If her services had been required in net that day, UNH would have been forced to take a delay of game penalty while she changed into her goalie gear or they could have played 'Extra Attacker' style with 6 players out and no goalie until she was ready to get in the crease. By the way, Meghara played net, as well as forward, in her younger days. She was not just winging it - she wore the pads in practice the week before the game in anticipation of being the backup.
Here's a link to the boxscore from the game in question:
https://www.collegehockeystats.net/18...s/wunhyal1.j08
And here's where it's mentioned in last year's NCAA rule book under Section 2, Rule 5 - Team:
5.3 Goalkeeper - Each team shall be allowed one goalkeeper on the ice at one
time. The goalkeeper may be removed and another player substituted.
A substitute goalkeeper should be on the bench at the start of the game
and shall at all times be fully dressed and equipped and ready to play. Upon
entering the game, the substitute goalkeeper shall take
his position without
delay. A team should not start a game with less than two goalkeepers.
If a team must start a game with less than two goalkeepers and the starting
goalkeeper is unable to continue (e.g., injury, penalty, etc.), a delay of game
penalty may be assessed if time is needed to have another skater change into
the equipment of the goalkeeper. Additionally, teams have the option of
playing with six skaters to avoid a penalty.
Except when all goalkeepers are incapacitated, another player shall not be
permitted to wear the equipment of the goalkeeper.