Before the weather gets wet, stuff some grease into the locks and also into the ends of the handbrake cables, if the rubber bellows are torn or split. Then squirt some WD40 in there tio dissolve the grease and carry it into the inner workings. Don't use just WD40 on its own... as it evaporates eventually. The idea is to use WD40 as the solvent to make the grease go where any water would.
Check your coolant.. and if it's 2 years old and blue, drain it all out (dispose of in an environmentally friendly manner - don't tip it down the drain, bury it or sell it to a Tramp..
) flush the system and then refill with new (pink) coolant at 50%. If you have new-ish pink already, top it up using neat (undiluted) pink coolant.. not the ready to use stuff. The neat coolant will give your existing coolant a boost.
Don't mix pink and blue.. in theory it can cause problems... in reality it doesn't matter.... but think what the end colour will look like!
In any case, top up the coolant and make sure the system is well-bled and that the thermostat works properly.
Give the beast an oil change and put 0W40 Synthetic in there. Eurocarparts.com are selling 5ltrs of Triple QX for £12.50 so, Yes, you can afford it. 0W40 can scamper around the engine much more easily than even 10W40.. never mind any heavier stuff you might be using.
While you're crawling aboot... get some underseal and touch in any splits in the rubber schultz underbody protection - the floor-sill joints, the jacking points and the footwell floor are all candidates for the stuff to lift and let the moisture in.
I would put a cable tie around all the rubber exhaust mounts since yours will be a bit perished already and the sub-zero cold, salt and then heating up and cooling down will stress them more.. and you really don't want to be lying underneath the car one damp November evening fixing one that snapped. The cable-tie will help support them.
Get some spare head- and tail-light bulbs since you'll be using the lights more and you just know that a bulb will "go" one Monday morning, leaving you with just one light and praying that the other one will last all week until the weekend when you can get to Halfords to buy a new one.
Put some concentrated screenwasher in the screen washer. Keep some de-icer in the car (but take it out and leave it by the front door at night, so that it doesn't get "locked in" to a frozen up car...
Get some tyre shine stuff and lube up your door rubbers, wherever the door or glass touches. This will repel moisture, so with the lubey locks, you shouldn't get frozen out.
Put a tyre pump in the boot, so that if you get stuck and have to let air out of your tyres to get traction in deep snow, you can pump the tyres up again afterwards...