Although based in Scotland, the Outlander team has ventured across the border into England in search of locations.
As of season 3, we are only aware of one Outlander location in England, Wilton House. Two of the rooms in this historic building were used to represent those in the Palace of Versailles. Also the impressive gardens and Palladian bridge were used for some outdoor scenes.
It is quite possible that more locations will be used in England. The obvious closeness to Scotland make this a definite possibility.