I would get it indoors first in a heated garage and if thats not posible, plug it in and leave it overnight. I would also pour in a 16 oz bottle of Stanadyne Premium fuel treatment tonight if you have it. Then tomorrow, pull the fuel filter and replace it with a new fuel filter. Make sure you pump all of the air out of the fuel system after you replace the filter. Then, give'er another try. It sounds to me like you may have some fuel gelling going on somewhwere in the fuel system or possibly air in the fuel system. Sub-zero cold air can make strange things happen sometimes. Good luck.
Happy camping!!! See y'all down the road!!!:)