After you leave the Farnborough west sector, forget military units like Boscombe and Yeovilton and don't bother Solent unless you actually wish to penetrate their CTA; first unit is Bournemouth (7 days) then possibly Plymouth Mil, who use radar heads at Portland and Plymouth so they can see you a long way down into Cornwall. If they're not available try Exeter. Culdrose might be open but don't count on it.
Oh and don't forget to check the activity state of D127 (Porton Down, just SE Boscombe) which can be active at odd times with a variable upper limit.