Keeping your home warm / heating / energy crisis / insulation etc

Re keeping the humidity down indoors, avoid drying clothes indoors if you can. Best solution is a heat pump tumble dryer if you can afford one and have the space. Ordinary tumble dryer is OK too but more expensive to run and you need to vent it out a window or keep it in a garage or shed, still vent it out a window or door though. Other alternative is to dry clothes at a launderette. We had to resort to this year's ago in a rented 1920s maisonette which had all external walls. Luckily I was an energy conservation officer for a London council at the time so I borrowed a logger to measure room temperatures and humidity for a few days!
Also have others have said, lids on pots when cooking. If you have kitchen and/or bathroom extractor fans, shut the windows and use the extractor fans to get rid of moisture in the air.
If it's your house, fit extractor fans in kitchen and bathroom if you don't have them, try to keep furniture away from external walls, insulate the house wherever you can, in particular problem areas you could try internal wall insulation.
Finally, don't turn central heating off at night (if you have it), turn it down to 16C to stop house getting too cold overnight. It will use more energy but it takes a lot less to hold a house at 16C than say 20C. If you can fit a wireless thermostat even better as you can move it to the coldest room at night time.
Appreciate all of the above costs. Condition of older housing in the UK is a disgrace, particularly private rented. Could be addressed by insisting on minimum efficiency levels for all rented homes rent but successive governments have avoided this as, we'll, they represent the landlord class!

Got a bit ranty there, hope the kids have recovered, love to rhe family!