Cancelling drivers license

As part of breaking residential ties with Canada, I understand a critical factor is the cancelation of the drivers license (Ontario law actually requires notification within 6 days of any address change). How is cancelation done exactly, and if one returns in a couple years, does relicensing mean starting from scratch in the graduated licensing program (in Ontario at least)?

You don't need to cancel it, you'll need it in order to get a driver's license whereever you're moving to actually. When you move and apply for a new license, they'll take your Ontario one.

Well they [i]may[/] take your Ontario one, some DMVs will take it and return it to Ontario, others (such as California) don't and some just chuck it in the garbage I suspect. If you've still got it, return it directly. Basically this will only become a major issue if the CRA tries to deem you resident and you need to be able to demonstrate that you've done due diligence on severing ties.

Ontario recognizes US licenses, you just have to go and swap it, I think they require an abstract for certain States.