This is the CANADIAN football league. The CFL tried to expand into the US before and it failed miserably. There probably are more American fans now, but that doesn't mean it's a good idea.
The Grey Cup is a CANADIAN tradition. You don't take an event like the Grey Cup and stick it in Hawaii. CFL fans from across Canada go every year and it's a big event. It's also nice for the economy of the city hosting it. You pretty clearly have no idea what it means to Canada to suggest moving it.
And yes, the average Canadian will never go see a Grey Cup in another city. But a heck of a lot more will do that for the Grey Cup than go to Hawaii. Only real fans go. Just as it should be!
Yes, this is Canada's game. The CFL pre-season drew higher TV ratings than the NBA finals in Canada. Regular season games usually get higher ratings than the NHL. It blows NFL ratings out of the water. Just because there are some fans in the US now doesn't mean it's not Canada's game.
And if it doesn't work out and you "just fold the Honolulu team", it just makes the league look stupid. It would be a disaster to go there and pack up and leave a couple years later.
So, it's stupid from a business standpoint, the cities of the Canadian teams wouldn't want it, the fans in Canada who actually support the teams wouldn't want it. The travel becomes a nightmare for teams, too.
ArgoT's ideas might make it plausible financially, but it still makes absolutely no sense whatsoever.