Well so your back to gps or raw data vor/ndb/ils tracking. I would suggest using both... you never know what those americans are doing to the signal ;-)
I dont really understand the problem... you wouldn't / couldn't proceed all the way to destination, unless you are very close to it.
Its not yet allowed to fly a gps approach so you would need rawdata for this. With regard to airways, I think you could use gps only.