Honestly the way I tend to do this is put a pair of thinsulate gloves on inside the fingerless leather, and just accept that my fingertips are going to get thoroughly sodden; but it might actually be worth putting a pair of normal leather gloves inside a slightly-larger-size fingerless pair, which isn't something I'd really considered before.

Otherwise it bumps the price up a bit, but using the keyword "tactical" (as in "tactical leather gloves") gets you a lot of really heavy-duty durable stuff.

(That's about where my suggestions run out for right now, I think...)