You are on the right track using Transferwise or a Forex broker. That's what we did to move the house money.
Since then, I have used Norbit's Gambit (at TD, but Questrade will help you too, TD over the phone support was amazing for this). So, definitely look into Norbit's Gambit. Really, I had the money in cash in the USD account, a phone call, and (after waiting for it to clear), money in the CAD account. Done and done. Having it at TD meant that it was linked to a TD chequing account and I could online transfer it there, and take it out via ATM or cheque or whatever. My primary banking is not even TD.
Strategy -- The key strategy here, as someone who thought they could relocate for a few years and get a currency exchange benefit -- is don't count on it.
Move the $'s into CAD that you will live on while here. If you plan to retire here, or will travel here a lot in future years, then have a portion of your retirement in CAD $'s so you can outlast a 7 year period of poor exchange rates. You can invest in US companies / ETF in CAD dollars, for a tiny MER penalty.
Like the others say, only put 25% into CDN stocks. The rest can be CAD dollar ETFs on US or internaitonal indexes, for money you want to eventually spend in Canada. Keep USD for money you want to spend in USA. You can set up USD trading accounts within your Canadian brokerage accounts and avoid exchange rates.
It sucks to have your foreign investments gain 40% over 8 years, yet be 10% down in the local currency that you want to spend it in.