Found this Notam when idly flicking through the paperwork on the way down to the Canaries yesterday, may be of interest...
GCTS REF/AIP AD2-GCTS1 DATED 06-SEP-01
FUEL AVGAS 100LL COMPLETELY WITHDRAWN
VALID FROM 1600 19 SEP 2001 VALID TO PERM (A4531/01)
so I had a look in the other books, You can get Avgas at Las Palmas (GCLP), Lanzarote Arecife (GCRR), and Tenerife North (GCXO)
so no avgas at the other airfields
Tenerife South GCTS
Fuerteventura GCFV
Hierro GCHI
La Gomera GCGM
La Palma GCLA
If you are confortable with long overwater legs I'd route Faro to Porto Santo or Madeira (formerly Funchal) for a nightstop and then on to the Canaries. Don't know about the fuel situation in Madeira, sorry.
If you can't get through on the radio we'll be happy to relay if we're about. Callsign Jetset (Air2000)
Good luck