Having done a few similar trips (Northampton to South Coast) here's my advice FWIW:
I can highly recommend signing up with Electroverse, and getting their app and RFID card. It has made our public charging experience much simpler and more reliable. They seem to be partnered with most networks and they sometimes have cheap rates on offer. Electroverse are associated with Octopus, but you don't have to be an Octopus customer. There are good video tutorials online.
I am going to make some assumptions about your trip, in that it's a holiday and you will be doing a bit of running around while you're there for a few days. This is how we have handled similar trips:
Charge the car to 100% the night before your trip. This maximises your cheap rate home charging, and removes any possible range anxieties (diversions, use of A/C etc.).
The Trophy will make that distance easily in one go, you will probably have about 40-45% left. If you have a destination charger available, use that to replenish. If not, I would aim for a stop around 15-30 miles before your destination, and then top the car up to a level which will leave you with near to 80% when you arrive. This leaves the battery at its max "health" level and gives you plenty to run around with for the duration of your stay. We like to time the stop with a meal, or at least a coffee. We have found it best to use places with multiple rapid chargers to minimise the chances of having to queue.
For the return journey, it has usually turned out that using the same/similar charging location seems to work. Aim to get home with >20%. This will depend on the amount of charge you used while away, etc.
I tend to use the Electroverse app or ZapMap to located rapid chargers in the desired location, but then personally I just locate the charger on the car's built in Satnav and use that.
For long trips I use ECO mode and Regen A on the motorways (and use ACC), default Normal/3 the rest. Seem to get good figures this way.