It depends on the year of the bike. The additional fuel enrichment by the computer cuts-out at coolant temperatures about 65°C. Before 1995 or so, enrichment continued until 85°C.
On cooler days, you should expect to see lower coolant temperatures. Unfortunately if you run too cool, the bike isn't operating at it's best efficiency. In this case, the most practical solution is to cover a portion of the radiator to reduce cooling air flow and raise the coolant temperature. How much radiator area you cover depends on how low an ambient air temperature you expect. You'll make your best power at 85°C. Trucks in arctic climates, for example, will run with 90% of the radiator covered.