I drive trucks at Night & have seen Night flying at Sherburn in Elmett while passing on the A1 near Ferry bridge. There were three in circuit last night. Give them a try as i also saw several up last week too.
Also my club at Sandtoft have been doing night flying on Wednesdays.
Hope this helps you although you will only have two weeks now till BST starts & i think not many will be night flying soon due to lateness of sunsets.
Trev