Has there ever been a Stanley Cup champion with such a small dude logging 20+ minutes?
TL;DR - Yes, but not since 1990. Matt Grzelcyk and Ryan Ellis are the best comparables.
I'm not a G hater, but I was curious to know the answer to this. I think the primary issue with G's size is weight, not height. Guys like Boyle, Campbell, and Rafalski were all listed between 190 and 200. G is listed at 170. That's a very big difference. I know those numbers can be inflated or deflated by the team. Nevertheless, I looked at defensemen who played at least 20 playoff games, were born after 1939, and were listed as weighing 180 or less. This is what I discovered:
There are only 26 players who meet that criteria. Only five of those guys won Cups:
1. HHOFer Jacques Laperriere (6'2", 180) who won a bunch with the Canadiens in the '60s and '70s.
2-4. Don Awrey (6', 175), Gary Doak (6'1, 175), and Dallas Smith (6'1", 180) who won the Cup together in '70 for Boston. The average size of their D was 5'11", 187. Awrey and Smith won again in '72 with Boston. Awrey won a third with Montreal.
5. Reijo Ruotsalainen (5'8", 165) who won Cups with Edmonton in '87 and '90.
There are only four recent players (besides G) who meet that criteria:
1. Jared Spurgeon (5'9", 167)
2. Kris Russell (5'10", 170)
3. Matt Grzelcyk (5'9", 174)
4. Ryan Ellis (5'10", 180)
Both Grzelcyk and Ellis have been to and lost Cup finals. In 2019, Grzelcyk averaged 16:27 ATOI in 20 of 24 games playing behind McAvoy, Krug, Carlo, and Chara. He tied for the worst +/- at -3 but had 8 points (tied for 2nd among Boston D). In 2017, Ellis averaged 23:26 playing with Josi. Subban/Ekholm was the other top pair. All four had about the same stats.