By accepting US or Canadian Passports and acquiescing to this solution would essentially have ceded the issue of sovereign recognition on a very significant level.
They are NOT part of the US or Canada, they have their own sovereign nation and should be recognized and accepted as such!
So the Iriquois have already seceeded. Can we join?
Ok. Like I said, if they want to be a separate nation, then be a seperate nation, with all that entails. Some (perhaps even the majority) people in foreign countries wait months and years waiting for a visa for entry. If the Iroquis tribe wants to be a nation, they can't expect to be treated any differently than the other nations who don't have formalized relations or treaties with the UK.
There's an old saying that's probably appropriate here - be careful what you wish for, you just might get it.