Personal viewpoint only, but given the low cost of the belts and the relative ease of changing (make sure you are careful on the alignment of all the gears), in your case I would look to change in the next year. If you regularly start the engine and exercise the belt then I would expect that with your mileage it should be good for at least a couple of years more if you wanted. If it is stood for long periods, then I would probably change sooner.
As mentioned if you are unsure of the tensioner bearing, I would take the opportunity to check and replace if in doubt.
Peter