unless their sleds were in a bad spot......ridge top, avy chute......etc, leaving them was the first mistake.
rotten logs will not burn well, they lack the fuel to actually make much heat, don't waste your time.
in order to build a fire that is going to actually last in snow you have a few options, dig to earth, build a log base to start from, or have a bunch of fuel handy and keep it hot.....the first two are the best choices.....the order will depend on conditons. digging to earth is pretty self explanitory, but keep in mind that air circulation needs to happen, so a line in and out in the prevailing winds direction will be a good move in the long run. to build a platform, cut or break as large diameter logs as possible, limb them and place them as close together as possible. two or three layers is bettter yet, alternate directions as you stack and it will allow air into the bottom. you whole entire goal is to get a coal bed going that can overcome the conditions.
fire requires the following for it to occur:
fuel.....gas, oil, wood, dorito's.......anything thatwill burn.
oxygen.....the more the better
heat...fire does not occur with out heat, flammable liquids don't burn till they reach the flash point, so why would wood.
ignition...this could be the bic lighter in your pack, a flare, a spark stick, a spark plug....you could also get to the auto ignite point of your fuel.
if you take any one of those out the fire can't happen.
so now we have a bed, and the solution to how we get flames, butwe need to address fuel......if it is very cold it is much easier look to the lowest small branches of fir trees. the dead branches will break easy and burn well. there is also some "fur" that will burn well. when you think you have enough.....get 5x more. pitch balls are also great, grab all you can. you must be thinking about how the heat is going to warm all you kindling and how is it going to circulate air...a tipi, or criss cross would be wise. have lots of fuel and start as small as you can with your kindling....remember you are trying to get a coal bed going, and untill you do your fire is in jepordy.
ok lets say you now have a coal bed on a log bed. you need to keep it going as big as it takes to keep a coal bed hot, if you dug to earth it will not need to be nearly as big as if on a log bed.
keep your wood on the opposite side of the fire and try to arrange it to reflect heat back to you. having the same behind you helps too, of course by now you should have a pit or debris hut built.
the golden rule is to keep your coals good and red, if they start to die you better fix it fast.
vasoline and cotton balls works great for fire starter, a tampon in the fuel tank, or oil tank is a great tool too ( you do not have to use it all the first time)