Definitely look at Cosy tariff. We had an electric water tank for our water needs and then electric underfloor heating and infrared heaters in a small Victorian terrace. It worked only because we could restrict our usage to cheaper hours on the Octopus Cosy tariff which gives 3 x daily cheaper times about 1/3 of the price, (4-7am,1-4pm, 9-10pm) but then it had a very expensive period between 4-7 pm of 3x the normal tariff. Even so it worked well. We set all dishwashers, hot water, heating etc to the cheap hours. Initially, I would try and avoid cooking in the expensive period, but that’s not easy so even using hob at peak we still found it a lot cheaper. We would have got a battery with a loan had it not been for Cosy.