@Steven-8 I doubt that you would like to do the shortestn usually most boring, route.
I would enter my start and endpoint (london and nordkapp) and let MRA calculate the shortest route.
Then put a waypoint visually in the middle of that route, then another on the lower half of the route, and one on the upper half. That should give you stretches of around 1000 km. Cut that in 3 visually and you have parts of 300km on the highway.
That is 5 minutes work with a bit of experience and a good start. Combine two stretches and you have a 600km highway day,