The calculated distance (air line) between Henley-on-Thames and Stoke-on-Trent is approximately 115 miles respectively 185 kilometers.
By car or train, the actual journey to Stoke-on-Trent is certainly longer, as only the direct route (as the crow flies) between Henley-on-Thames and Stoke-on-Trent has been calculated here.
Air line (approximately)
185 kilometers
100 nautical miles