We had a fire in next door neighbour a few years ago, fire department was here in less than 5 minutes- central London. That was reassuring.
We have:
2 x fire extinguishers
Carbon monoxide detectors
Motion sensing lights
House alarm
Camera for front door
Need fire blanket- have been intending to get one for years
Torches
Candles, bottle water, few long life foods
Pepto Bismol, cough syrup, paracetamol, plasters, alcohol wipes, burn gel
In the car - blanket, umbrella, windscreen cleaner, small first aid kit, de-icer, ice scraper, pencil and paper, breakdown info, hand cream, lip balm, tissues, mints, gum, spare change, a £20 note hidden, sunglasses, few bottles of water, plastic spoons, and about 4 lightening charger cables (We drive a lot)
Not over prepared at all.