> we can expect high electricity prices to coincide more and more with times when renewables are producing very little power and low prices with times when they're producing lots of it.
Yes to some extent that's true, and we should expect demand management to play a big role in reducing the impact on ordinary households. Alec Watson (Technology Connections) did a video about how his home is set (in summer) to cool over night when power is cheap, so he wakes up in a cold but not yet uncomfortably so house, and during the day the cooling is off, so it gets warmer but unless the day is especially miserable it still isn't actually hot inside until the evening, at which point electricity is cheaper again and it begins cooling back down. This way he gets air-conditioning, in a climate where it's not entirely essential but certainly desirable, yet doesn't pay peak prices for it like his neighbours. Imagine if more people did that!
The UK could use a lot more storage. What it has is mostly black start capacity re-purposed as normal storage, but it is a bit short on non-picturesque mountains to modify. It also, of course, decided it didn't want to be part of the EU, where there's an entire continent of renewable energy sources to trade with, several hours difference in dawn time and considerable variation in weather - the UK is still connected to their grid with several Gigawatts of ties but now trades as an outsider.
Most homes in the colder areas of the US heat with gas because the cost per joule of gas is a lot less than for the equivalent electricity. But a lot of homes can supply most their heat with electricity, and would if the economics made sense. And even more would build that capability if gas was 2x the cost per joule as electricity.
A modern home boiler is very efficient, because what you wanted was heat, which is exactly what you get by burning gas. The gas turbine at a power station has to do the same conversion (burn gas to make heat) but then also convert the heat into electricity, and that's before transport loss.
In the ideal world, the choice is between "Burn gas in your home" (bad, accelerates climate change) and "Use renewable electricity" (good, although maybe expensive depending on policy decisions). But for many people today there is no choice, resistive electrical heating would still burn gas in a power station and just cost them a lot more.
Heat pumps tilt the scales, if they're practical for you, it really is possible that a heat pump running on electricity that's actually produced by burning gas works out cheaper and more environmentally friendly than just burning the gas yourself. And of course a heat pump powered by wind is entirely practical and potentially quite cheap.
A gas-driven heat pump could be even more efficient; that is, it could deliver > 100% of the thermal energy content of the fuel to your home (in the form of low grade heat). This is a consequence of avoiding, at least partially, the large second law loss in a typical furnace where very hot flame transfers heat to rather cool air. Any time you see a large entropy generating process like that in a system it's an opportunity for improvement.