I've used deerskin gloves for years. The roping gloves found at whatever version of cowboy supplier you have in your neighborhood are good, and slightly lesser quality versions can be found in most hardware stores for less money. I buy them skin tight at first, and they loosen up slightly with a little use. With tight fitting deerskin gloves (no wrinkles) I can get things out of my pocket, like my knife, I can work, which means getting nails and tools out of my nail bags, and manipulate fairly small stuff. They arent terrifically warm, but enough to do things that need some feel. I can usually get by with them down into the 30's pretty well. One of the chemical warmers in the pocket (or mitten) to warm up some may help, as someone said.
In deeper cold, and not always needing to manipulate small things, good mittens are best. Mine are deerskin outside with heavy wool insides. If you get them large enough, you can wear your deerskin gloves under them. I've long used eskimo type strings on mine, like the cord you had when you were a kid. The cord I use is a stout leather cord (good quality boot lace), with a sliding cord that slides up the front to keep the long cord from slipping over your back. When you need to take a mitten off, you grab it in your teeth, pull your hand out, drop the mitten, and it's there again when you need it. Very handy for hunting, or doing about anything else where you may need your hand in and out. Also, when it gets too warm to wear the mittens, you can just slide the front cord down to keep them from swinging around too much, and forget them til you need them again. No way to lose one mitten either. I tie a loop in the neck cord and hang them on a peg by the door when not needed.