The shanks of HSS drill bits are not hard. They're left soft for toughness and so a chuck will grip. You may get away with silver brazing HSS lathe tool bits (I've done it in a pinch), but it's not recommended. If you have a machinist friend who can supply with used end mills, they are hard end-to-end. You can buy "drill blanks", just plain rods, that are all hard.
You'd do better silver brazing carbide lathe or milling inserts to mild steel shanks. The problem then becomes sharpening. A diamond wheel is by far the best option there. I think a CBN wheel will work, but not great for the wheel. You'll see silicon carbide ("green") wheels for carbide, and they work OK for metalworking tools, but I think you'll have difficulty getting a keen enough edge for woodworking.
If you want to play with the carbide I'd be happy to send you a few inserts if you PM me your address. Some would require brazing, some have a hole so they can be screwed down. A friend made some very nice large turning tools with inserts I gave him. He used a lapidary diamond wheel to shape/sharpen the tools.
Is it difficult to mail a couple ounces over the border these days?