Don't even think of it without GPS and radar cover. In theory you could fly VOR radials off CPT and SAM but I woudn't recommend it unless you were desperate.
Okay - so we can forget about the VOR/DME at
BNN, the NDB's at
HENton,
BURnham,
West
COtt and
WODley.
We can also forget about the traffic or deconfliction service provided by either Farnborough Radar on 132.8, 125.25, Benson on 120.9 or Luton 129.55 if they're not busy.
If you want to just stare head down at the GPS unit - pray that we've got a signal and that the database it is loaded with is upto date.
Use
ALL methods / facilities available to keep your spacial awareness and your options open in the event of system failures.
DD