Has it always run hot or is this just a recent development?

Because your over heating problem is occurring at highway speeds, the fan is not likely your problem. Compared to the airflow generated by the forward motion of the car at 110 kph, the fan generates squat. The fan is important at idle and in stop an go traffic. However, if you live in a place like where I live (the prairies) a radiator or condenser encrusted with dead grass hoppers will cause overheating because of reduced air flow. Check to make sure your fins are not plugged up with stuff.

Partially clogged radiator tubes can be a problem. On my 142, the bottom 1/4 of the rad had a plug about 1/2 way across the rad(the 140 has a crossflow radiator). If you have access to an IR thermometer this can be useful in determining whether you have relatively consistent temperatures from top to bottom on your rad or there is a definite cool spot which is a sign of a blockage.

The correct thermostat is important. Aside from the operating temperature of the thermostat, the thermostat has a little flap on the bottom which closes off a recirculation tube in the block when hot. This forces the coolant through the radiator. If the thermostat does not have that flap or it does not reach the tube, then some of your coolant will not be flowing through the rad leading to hot running.