@Wrangeld in addition to the suggestions above you may want to try adding an overflow tank. This really helps, had it on my jeep back home as that used to overheat even on the highway. Someone suggested this overflow tank and I gave it a shot. Never had an overheating issue after that.
Check on the suggestion provided by others, this should just be an addition to all that. You can go through the article at the link below that explains what this tank basically does.
https://cartreatments.com/radiator-coolant-overflow-tank/