Here's some miscellaneous, disjointed, ramblings smile ...I'm looking at this strictly from a survival standpoint. This might not be what you had in mind from your original post, but if it's not, it's an alternate view....if this is going to be a SHTF defense gun (this is ETS Forums, right?), then ammo supply will be extremely important. If you might be on the move, you are going to want a calibre that is readily available. AFAIK, Canadian military forces predominantly use the C7 & C8 carbine, both chambered for 5.56x45mm NATO (similar to .223). They are basically AR15/M16 rifles and carbines. If you want to be ETS, rifles in those calibers would be high on my list. You will need to be able to find/buy/barter for readily available ammo. Parts availability is also important. Can you readily get parts?
In my collection, I have an FN PS90 carbine. Great little weapon for what it was designed for (CQB)....rear echelon troops (cooks/medical/support/messengers/etc...) who could not carry around a full sized battle rifle. Superior to a 9mm pistol against adversaries equipped with body armor. Almost no muzzle rise or recoil. Stays where you aim it, on target, even in full auto. Great all around carbine IMHO for plinking and home defense. Only thing is, replacement/repair parts are ONLY available through FN, and that's if you ship the whole carbine back to them. In an ETS scenario, that probably won't be my go to gun. I'd probably take an AR15 or an AK47 variant, with the AK better suited for taking game (there are better calibers for game mind you). I do recognize though that AK ammo and parts would not be readily available in a SHTF scenario.

For example, you might have an old .303 Enfield rifle that you love, but where are you going to get ammo for it? You're not!!!
You might also want to consider any other family members who will possibly be firing the weapons. You could get a 30.06, which is a large caliber round and will take pretty much anything you hit with it that you are likely to see in the Canadian wilderness, but is the wife or kids or someone of small stature going to be able to hit with it? Are they going to be flinching, with closed eyes, every time they pull the trigger?

Also consider weight of the rifle. If this is a SHTF scenario you are gearing up for, and you might need to be mobile, you will probably be carrying a pack of some sort, and it might be a huge pack. Keep in mind how much weight you can physically carry. It not just the rifle's weight, but also the weight of the ammo and any magazines, cleaning kit, optics, etc. An M14/M1A in .308, another great, relatively flat shooting round, weighs 11½ pounds. Compared to rifles in the 6 to 8 pound range, that's a lot of extra weight to lug around on a daily basis.

If you want to put an optic on the rifle, don't at first. Learn to use your iron sights well. With Murphy's Law, your optic might go belly up at the most inopportune time, and if you aren't well versed with shotting with iron sights your SOL. Shot placement is extremely important. even if you are carrying a small caliber, you can make it work better with accurate shot placement.

Try before you buy...Like someone above mentioned, join a club, buy some different calibers of ammo and try some rifles.

Some of my choices (you know what they say about opinions)of ETS arms would be an AR15/C7/C8(any reputable brand), AK47 (Arsenal brand makes some very inexpensive, top quality versions), Ruger 10/22(can carry lots of ammo for small game, and stinging larger bi-pedal varieties), and any major brand of 9mm pistols(easy ammo availability). Identical rifles for the whole family could be good or bad. Good for parts availability, to keep at least one working, but bad if the one caliber is not readily available when you need it. Also consider that a break down rifle is able to be placed in a pack, for concealed carry, when hiking through the woods, hidden from view of those you encounter (with a concealed pistol at ready on the hip).