I don't know if anyone has put together a comprehensive list of the expansion, but here's a few ones that are opening soon, according to Welcome Break services.
Newport Pagnell (Southbound)
Woodall (Northbound)
Leicester Forest East (Northbound and Southbound)
Fleet (Southbound)
Warwick North & Warwick South.
Newport Pagnell (Southbound)
Woodall (Northbound)
Leicester Forest East (Northbound and Southbound)
Fleet (Southbound)
Warwick North & Warwick South.