When I was a boy...used to run a splash of meths in the petrol for skidoos in Svalbard because we were constantly filling from jerry cans in all sorts of weather - theory being that the snow that got in to the tank would melt, be dispersed by the meths through the petrol and pass through the engine without killing it rather than building up in the tank till it would make it in one non flammable lump into the cylinders. We had our share of things going pear shaped on the skidoos but don't remember actually having any stopping because of water in the fuel.
We were also running diesels with rather a lot of petrol in the fuel and cooking on Jet A1 which sounds dramatic but is only posh paraffin.
