Heading North

First of all, congratulations on sobriety. Sounds like you had a great support system and, more importantly, you were willing to accept help and interested in change. 

In response to your big question about how you know when you are ready to leave home - Most of us don't know. Some experience something so uncomfortable (eg. big fight with parents) which pushes them out. Others have a calling to walk the earth and explore. But unfortunately, there is no explicit alarm system flashing a big red light indicating it's time to jet. 

What to do? Maybe consider this a great experiment. Moving to Canada is an experiment on self-reliance, sobriety, independence, and exploration. Maybe give yourself a time frame within which to conduct this experiment by. If at the end of the time period you have not felt like you've achieved some level of security with yourself (...or you get tired of being attacked by grizzlies and moose), have a Plan B in place - maybe moving back home or maybe trying a new spot. Talk with your family about this plan. Let them know what you're thinking and make sure moving back as a Plan B works for them. 

From a more philosophical perspective...There may be more that you're seeking in heading to into the great North woods than you realize right now. So often, we have an instinct to have great big experiences, challenge ourselves when we feel flat and stagnant. We call this the Classic Conflict. Man vs. Man (society). Man vs. Self. Man vs. God. Man vs. Nature. One of the first written stories was about this very issue (google Gilgamesh) as well as Star Wars believe it or not. But, as Nietzche said, ...when you gaze long into an abyss the abyss also gazes into you. He was referring to not being corrupted by our desire for justice against those we despise and feel have violated us. I think there is also a case to be made his quotation is relevant to those that run from or to something. The isolation that will protect you from drug dealers and naughty choices may become more and more like a prison and turn on you if you are not prepared. 

This is where I recommend participating in individual counseling. Not substance abuse counseling, not NA or AA, but individual counseling. There will likely not be any therapists in Northern Canada. But until you leave, consider talking with someone about your future and how you can identify your values, your interests and possibly some longer term goals. This will likely anchor you during some dark moments ahead. Make sure that when looking for a mental health professional you interview them instead of only checking to make sure they accept your insurance and have an opening. Is their style congruent with your needs? Do they have life experience which makes them a deep-well of knowledge and processing? Do they have impecable boundaries and maintain a professional distance? These are just a few questions I recommend asking. 

Best of luck. Stay warm. Don't let the black flies and mosquitos drive you nuts.