If the power goes out, you need to think in terms of what will be missing.
Lighting.
Heating.
Cooking.
Other stuff.
Lighting
torches are best rather than naked flames, although if you can have candles in proper holders and stay in the room with them, or proper oil lamps, they are also useful for rooms you are using for a long time (the kitchen or sitting room for the evening - not so much for bedrooms). Bellini's idea of a large plastic bottle of water with a headtorch turned into it is a great one to give a gentler light for a larger room, a great camping trick!! Remember to have some spare batteries for whatever torches you have. Torches that are powered by dynamos (wind up), often sold for DCs, don't need batteries. Solar powered lamps are also useful.
Heating.
Do you have alternative sources of heat? Gas or oil powered central heating? A wood burning stove (and wood for it)? An open fire with coal/wood/turf to burn?
Extra blankets are useful, and wearing plenty of layers to keep yourself warm. Hot water bottles can make a difference.
If you are really stuck, google terracotta pot heaters, as with 2 terracotta pots and about 4 tealights, you can get surprisingly warm in 1 room.
Cooking.
Do you have just electric cooking? Or do you have gas cooker?
Do you have access to any camping gear, like a single gas ring burner? Do you have a BBQ in the garden, whether gas or charcoal, and fuel for it? If you have a wood burning stove, does it stick out so you can put a kettle or pot on top of it?
Keeping cold:
This is mostly keeping food cold.
Keep the freezer door closed as much as possible, and the fridge also. It could be useful, if you have a cooler bag or box (and especially if you have some ice cubes, or ice blocks for camping already frozen to add into it), to put the most frequently used things into that for regular use to keep door openings to a minimum - milk, butter, juice, things for today's planned meals etc. In fact, if you are taking things from the freezer for today or tomorrow's meals, it would be a good idea to do those early and allow them to defrost in the cooler (or the fridge if you don't have a cooler) - to help keep other stuff cool while the frozen stuff defrosts safely. Also, improving the insulation (to keep the COLD in in this instance, rather than heat in), can be done by covering the cooler with a well tucked in blanket/large towel, or even a few layers of newspaper.
If you lose all cold, as things warm up over a few days, use a large bucket/basin of cold water to stand things like milk and butter (well protected against the wet - perhaps in a plastic tub) to keep them colder. Again, another camping trip.
Entertainment -
Do you have any powerbanks to be able to recharge phones etc? Particularly any that can be recharged by solar power?
A battery powered radio is a good idea to be able to keep in touch with the world. And spare batteries. Or a wind up radio.
Perhaps try to restrict use of ipads/phones etc in the meantime, so that any charge can be kept to allow some fun intermittently.
Have some things that need no power to entertain - board games, cards, books, jigsaws, craft materials etc.
However, other than thinking about a few things to plan in general along the lines above, don't worry about it too much. We are more likely to lose power for things like bad weather, when snow or high winds bring down trees over power lines etc. Utility companies are part of the essential workers, so there is far less likelihood of a powercut, or at least a serious powercut lasting more than a couple of hours, due to the current virus issues. And also, as the spring is now definitely coming, the evenings are brighter for longer and the weather is warmer also so if a powercut did happen, there would be less to worry about than if it was the depths of winter.