I am a southern Ontarian so following is just smoke from such:

N.Ontario does not need duplication of bureaucratic offices instead it needs recognition that the money that it contributes to Ontario as a whole should stay in the north to develop infrastructures.

Ontario Ministries dealing with forestry and mining or similar should stay in the north. There were moves to Sudbury and Thunder Bay but these are still like southern to many northerners. Northern Ontario has a problem of physical size versus low population density. No matter what you move there it is still far for most of the people.

Solution is fast development of transportation and communication but how do you afford such if your tax base is relatively small.

Auminer how correct you are in this:
"The Americans benefited from Ontario's resources a lot more than Ontario did and that would not likely have changed even if the North had been a province."
Imho, If north had been independent from the start it would have been taken advantage of even more. The smaller you are (here population wise) the weaker you are.