Say I want to build a couple mines out in a remote area, because there are no good spots near my main town. If I build a few houses and a mine out in the middle of nowhere, what buildings should I build with them to maximize their productivity and survival chances? A barn and a stockpile sound critical, but I'm not sure how citizens choose between nearby stockpiles/barns and remote stockpiles/barns. Is anything else necessary?
Citizens need a source of food and warmth to survive. Since the Help Menu states that citzens will only visit the nearest storage barn to collect resource then you can't depend on citizens going to your primary settlement to get resources. Even if they do take the long walk back to your primary settlement they will be wasting a lot of time doing so.
Your best bet would be set-up a Market near the offshoot settlement to ensure all the goods the citizens need are close by. Market Vendors will gather resources from Storage Barns and Stockpiles all over the map, so it'll ensure that citizens will always have the resources they require near by. The long travel time between the Market and your primary settlement could still cause some problems though, so you may need to put several vendors in the Market to ensure the Market always has a sufficent number of supplies.
Another option would be to build a gatheres hut, forester and woodcutter. The gathers hut combined with the foreseter replanting trees should ensure they have enough food. The woodcutter and logs provided by the forester should ensure they have enough fuel to keep warm. I suspet they won't have access to clothes with this method, but that will just decrease their productivity. So long as their homes are warm they won't die they should just work less and spend more time indoors where it's warm.