I never found metalgrip, but using gflex and ptex I never had a repair fail. I put the gflex in, and right away I melt the ptex in. My reasoning is that the ptex gets glued in by the epoxy this way.
On big holes I found sometimes it's hard to work the ptex in if it's wider than the iron tip. This is where I roughly melt the ptex in with the iron, then with a heat gun and a metal scraper I press the big patch in. Your hole does not look like it's that big. This place has gflex for a very good price
https://www.google.ca/maps/place/Th...5eb5fca68c6f98!8m2!3d43.6387463!4d-79.3889441
I really enjoy "survival" skiing in chutes, and rocky tight spots. I did have to do quite a few repairs
So what's the best resort around the GTA(milton) to go for a beginner. What's closer than blue but does not require a club membership? Glen eden is probably the best bet?