Monday's 1-0 win over Concord Rangers - last season's delayed final - earned the 19-year-old his first piece of senior silverware. Harrogate also made history, becoming the first EFL team to win non-league's showpiece final.
McPake's parent club are two games from going unbeaten in the Scottish Premiership this season, having wrestled the title back from Celtic for the first time since 2011.
Yet, after five months in north Yorkshire, the Scotland Under-19 international has his own success story to tell.
He said: "No matter where you're from, everyone dreams of playing at Wembley Some boys go through their whole career without playing there so to do it at 19 and win a cup final, I couldn't ask for any more.
"At 19, on a six-month loan, to get to a cup final at Wembley was unbelievable. If you told me that at the start of the year, I would have taken it all day.
"The experience, the build-up, the game and afterwards - I'll remember it for the rest of my career.
"I feel I'm twice the player I was. Going on loan is so valuable. I was 17 when I first went out so I was pretty young.
"Most boys in England don't go out until 19 or 20 so I realised how important it was to go, learn, have disappointments, have setbacks but see the highs.
"Playing first-team football is the most important thing you can do. The best thing I've done is get away. As good as academy football is for your development, by a certain age you need a certain amount of experience because that's what managers look for, they want to trust you."
Four goals - including Harrogate's goal of the season against Bradford - in 24 games have earned the trust of boss Simon Weaver and caught the eye of English clubs.
With a year left on his contract at Ibrox, McPake could have a decision to make this summer but believes his spell at Wetherby Road - helping Town to a comfortable mid-table finish in Sky Bet League Two - has helped raise his profile.
He said: "I've got a year left on my contract at Rangers and coming down to England has been a great experience but also exposed me to a new market as clubs are always watching the games in League Two.
"Rangers have kept a close eye on me and I really appreciate it. It's good to know they are still looking after me so I will be back in for pre-season and I'm sure we will have some conversations about the future. They've told me to keep doing what I'm doing."
For now, though, McPake is eager to see more of his adoptive home ahead of Saturday's final game of the season at promoted Cheltenham.
He has been living in a hotel since joining Harrogate in January and has been unable to get to know the town due to coronavirus restrictions.
"I want to get out now and see Harrogate. With the Covid restrictions going away, in my last week I'll at least see the place," he said.