Well here is my 2 cents, but only because you asked.

I have an affinity for vintage single shot rifles but I think that the best modern designs are a bit more robust. If you are looking for a rifle you intend to shoot regularly, especially with high pressure cartridges, then I vote for modern metallurgy.

Your stated purpose is "primarily be used in North America for deer, pronghorn & elk". For that mixed bag I would look for something flat shooting enough for pronghorn, heavy enough for elk, that won't blow up on a close-in deer. The low side would probably be the 270 Winchester, the various 7s would be in the middle, and the various 30 calibers at the top.

I am a fan of the 300H&H and I heartily recommend it. It will do all that you require and more. It will reach way out but it will not beat you to death with recoil. It's very capable as an elk cartridge but not overly powerful for deer. It is right at home with bullets from 150gr to 220gr and can do a decent job on bullets bigger and smaller than that. The long sloping case works works beautifully in a single shot rifle. Unless you shoot competitively, the throat, rifling, and bore won't shoot out before your days on earth are over. If you ever want to sell your single shot it will get snatched up in a cloud of dust. Nice 300H&H rifles always sell fast.