I have bought several pairs of these over the years and find them a perfect balance of warmth, dexterity and price.

I'm due for a new pair, but my usual sources (Amazon and EBay) don't have them in XL.

If anyone has a source or knows of a suitable substitute, I'd appreciate a lead.

I bought a pair of Firm Grip deerskin gloves from Home Depot. I have never worn a pair of Fownes, but these are pretty great gloves for $25.
Good dexterity, super comfortable, and plenty warm.

That said, your climate and mine are quite different. These aren’t a lined glove, they are just a piece of deerskin, so they may be a little under insulated for your area. They are worth checking out if you’re in the Home Depot.