The official range for the MG4 is 218 miles or 281 for the extended range model. I dont have any experience of the MG4 but my baseline for 70 mph real range is around 70% of official figures so at 70 your probably looking for a recharge at around 140 miles190 extended range. Your second recharge will be around 240/ 310 miles.But 200 miles @ 70mph is a three hour journey. Most larger EVs are in the 250 mile range now including the very good value MG4 long range (£28k). At this point you really should be considering a proper break so why not just use it to stop for a coffee and a loo break at a rapid charger where you’ll probably add another 2 hours worth of range. Grab a meal and you’ll probably be adding another 3 hours of range.
For regular journeys such as a drive to my Brothers house in Cockermouth Cumbria (376 miles) it is doable but its in reality a pain in the arse especially when you start to hit queues for the chargers.
Unless you can afford a premium EV like a Tesla the reality is its no where near as convient as an ICE where my only breaks would be a Costa in a village co-op off the A1 and a short walk somewhere in the Pennines.