The calculated distance (air line) between Poitiers and Montlouis-sur-Loire is approximately 60 miles respectively 97 kilometers.
By car or train, the actual journey to Montlouis-sur-Loire is certainly longer, as only the direct route (as the crow flies) between Poitiers and Montlouis-sur-Loire has been calculated here.
Air line (approximately)
97 kilometers
52 nautical miles