In the i3 (which I think has a similar motorway range to the e208 in warm weather?) I did a similar trip a few weeks ago.
I stopped about 5 min up the road from your planned first stop at the Instavolt at Penkridge – prob good to add to your consideration as a plan B / alternate - there are two units in a small retail park there with a Costa (with a loo) – unless you were planning on the pub for a meal.
If you did get to that point and still had a decent amount of charge/range; the Welcome Break at Corley has recently installed Instavolt units (x8!) in each direction. Note these are only 50kW though, if you want to reduce time charging and have a low state of charge, your e208 will charge much faster at a ≥100kW station, at least up until 50%.
If you’re not familiar, worth noting the “Charge Curve” of the e208 (i.e. how fast it will/can charge based on how full the battery is which I’ve linked below (source: https://ev-database.uk/car/1168/Peugeot-e-208)
The Milton Keynes Coachway was the second spot I chose to charge as there are a lot of chargers there. There’s been some chatter over on the other forum that the BP Pulse units have been occupied by local council staff but there are also 4x Ionity there which you can use with your Shell card.
Once you’re there it’s closer than you think to London and depending which area, you might be able to use Ubitricity (with the Shell card linked in the Shell Recharge app) to top yourself up while you’re parked here, if you can find a spot. Which part of London will you be headed to?
My almost-in-laws live in the Liverpool region so up and down the M6 is a familiar trip for me