Leave your nickels for Canadians, or just me, we are going to need extra now that we are rounding everything to the nearest nickel.
Canadians never really tended to hoard copper pennies, our pennies were always and still mostly are considered inferior to British pennies. The 9.4 gram 654 million mintage year of 1967, the last year the Brits made the "big pennies" means there are still quite a few lingering around if you know where to get them. The 7.12 gram two pence made of copper was still around until 1991, and easily magnetically sortable, unlike US and Canadian zincers. Two pence being roughly 3 cents Canadian or 3 cents US at current exchange rates.
Truth be known, if I were going for copper - I'd actually prefer a 1991 British two pence just for the 7.12 gram size (its a nice big hunk of copper) That you can instantly tell a whole roll is copper just by running a magnet over it also makes it extremely appealing (i'm not going to look at every date on every US copper coin if being used in a barter situation)
The least appealing of all pennies to me are of course the Susan B Anthony, Sacagawea, and Presidential US 8.1 gram pennies