For just still condenser cooling, an adjustable water valve (spring loaded ones or electronic) meters amount of water into condenser fro the chilled water main header and bypasses the remainder to temper the return water to the chiller. Or you can set a water valve downstream of the chiller to bypass some of the water/glycol return to temper return fluid before returning to chiller. Chiller pump flow without a reservoir should beat least double the flow required by still. Since most distilleries are crashing and doing a still run the same day, chiller tank will be coldest at days start, then lose some ground before making the still run, which is ok, since still doesn't need as cold a cooling medium. Similar to beer crashing, you can install a air/glycol subcooler to cool return glycol before returning back to cooling tank.
Lot of this has effect on the budget, so some thought should be given to future plans on expansion.