Certainly, you're not talking about working in the Bay Area because a $115K total compensation is borderline impossible to live on anywhere between SF and SJ.
Your thinking could be right, however I would say it depends heavily on where you're living now and where you plan on moving to. 70K CAD in Ottawa or Montreal is going to get you infinitely further than 115K USD in SF or SJ. You'd probably need closer to 200K in SF to match that lifestyle.
Instead of comparing your $70K CAD salary at home by converting to $52K USD at market exchange rates, you should adjust it via purchasing power parity (as you are looking to figure out how far your new pay would take you in your new home relative to what you have now -- not make a purchase in the other country with foreign money). $70K CAD, adjusted for PPP is $75K USD. If you did the same notional conversion for $115K USD in San Francisco (where real estate is 7X the national average price per square foot) you'd probably wind up at $50K.
Now if you're planning to save money and send it home, that's different.