That's a hard question to answer, as each side has different pors and cons, so it really depends on your playing style. The French are inferior in terms of numbers, and the difference becomes greater as the war progresses, however they also have - for the most part - better leadership and more irregulars to call upon. Their best bet is to strike hard early, then make the Brits pay for every inch they have to retake. The British have the opposite problem in that they have many troops, but their often poorly led formations can founder in the wilderness as the stuble around blindly. As the campaign goes on their numbers will begin to tell. The key is forcing the French to commit to large battles where you can destroy their precious regulars. Remember, there are three avenues of attack - Western Pennsylvania, Lake Champlain, and Acadia/St Lawrence river. If you follow the historical strategy of securing these routes, British numbers will rule the day when French reinforcements run low. I wouldn't say it's quite like the brits in the Rev War, in that you know where your objectives will be from the start and there are a limited number of approaches into Canada, but parrying Indian raids and trying to mount strong offensives early are sometimes difficult. As the British, bide your time and defend your territory while amassing troops before marching north. Sorry for the long winded response, but i hope this helps.
