Well, not "survive" as a neutral picking fights with the big guys. You've still done surprisingly well taking over Scandinavia, Spain and Turkey.
I think the key is letting the Allies and Russia do the heavy lifting against the Axis and do one of two things:
1) Stay neutral and build up your "colonial IC" for a couple of years, especially in Spain and Turkey since these are almost untouchable. Be prepared to lose Scandinavia if the Germans jump, since beach defense along such long coastlines is ridiculous to even try.
2) Extend the Maginot to the beach, fort up with about a third of the army, and go after Italy with the rest. Their African and Med holdings are nicely scattered, susceptible to seizure one by one, and since you're a "neutral" power, you have the option to sue for peace if the worst should happen.
Just some friendly suggestions.