Strangely enough I have just been looking at the ID4 & the soon to be released 5 online and they are among the better looking mainstream EV's out there.
I am keen to switch from ICE to EV. I currently drive a BMW 320 M Sport and do c20k miles p.a with a minimum of 40 per day through the week and often up to 150 so no real worries there . Have it on a PCP which is comfortably affordable but clearly to go EV would require an increase in payment so from my viewpoint I have to be sure that the switch to EV would provide sufficient cost saving overall to at least keep my outgoings as they are now. With electricity cost breakdowns requiring a degree in quantum physics to properly understand it isn't easy to work out so taking that plunge feels a risk.
My main thought around range anxiety would be that I often travel from home (Brotton) to the Lakes and spend my days running around the fells or taking in a few of the towns so would need to be sure I could comfortably do 200 miles+ without the need to charge given I won't always be parking up in major towns or car parks.
For you:
ID4, assume 35kWh per 100 miles, so 0.35kWh per mile or 2.85 miles per kW (albeit the WLTP is better than this, around 4 miles per kW if you drive like a granny on slow roads)
20k miles = 20,000 x 0.35 = 7,000kW
7000 x £0.15 a kw = £1,050 in electric for the year, you may do some public charging but for you maybe <10% of your annual miles (I'm less than 5%), so maybe £1,100 electric for the year?
ID4 is an SUV, and SUV's not as economical as saloons, due to wind resistance and weight. So assume your 320 is 50mpg and SUV equivalent 40mpg
20,000 miles /40mpg = 500 gallons = 2,250 litres
2250 litres X 1.48 (av diesel price) = £3,330
So, you're easily going to save 2k, electric might go up, but it will likely come back down, diesel is only going one way.
ID4 has a useable battery of 77kW, but saving 10kW spare, even at 3 miles per kW that's 210-mile range, the WLTP milage is 320 mind, so you could get 250 in most circumstances.
As for the lakes, you may get there and back on one charge. EV's aren't the best at doing 80 on the motorway, especially not SUV's, in winter. But most of the A66 you will be down to 60mph (following a truck), and the lakes area way less than that and more braking, which suits EV's much better due to regen, so you should get there and back on one charge.
If you plan on doing lot of running around the ID4 can charge at 125kW an hour (so full charge in 40 minutes), albeit you don't get 125kW for more than half the charging time. There are no 125kW chargers over there mind, or along the way, but quite a few 50kW. So if you charged 25kW (a third of your battery) in half an hour, that would get you at least 75 more miles. So you could get a top-up on your way there, on your way back or whilst you're there. This would take around half an hour. It doesn't sound ideal, but there would be loads of chargers at 7,11,22,25kW where you could get topped up whilst you went for a walk of for some food etc. You could even charge at 2kW from any 3 pin plug, last resort but overnight will get you 75 more miles.
I've been over there twice, and mine has a range of about 200-250 depending how I drive it, I'm a bit closer than you, but not as economical, so I reckon your experience would be the same as mine. First time I topped up at Windermere on a 50kW, the second time I plugged in the 3 pin plug at the cottage thing where we were staying, neither put us out from what we would otherwise have done, and this is a worse case scenario I suppose.