Jump leads, shovel, blanket and ensure you have plenty of fuel.
I have rubber floor mats in the car which have doubled up as grip mats in the past and snow socks in both cars just in case - but never needed them so far.
Otherwise its all usual service stuff, tyres with decent tread, oil, water, antifreeze, screenwash at damn near 90% concentration so it doesnt freeze.
THIS
runs with M&S tyres all year round because it spends as much time off tarmac as t does on. Its light, its FWD and it seems to do allright in most things, I have even waded with it up to the depth of the headlamps (air intake is right at the top of the engine) and apart from jknackering a brake calliper it coped very well - carpets got a bit wet and the front crossmember is now a collection of holes held together by pig welds but hey, its a tough old thing.