Maybe not in winter but on a wet road/track could-it be faster than the Z06?
Wet road, yes, track, that's more tricky. It could be. But I'm guessing the difference is likely not a lot regardless.
I think this E-Ray needed to be one of these things to be relevant, noticeably less expensive than the Z06 (say $20K less), have noticeably better fuel economy (let's say similar to the difference between regular cars and their hybrid sisters, so like 20% better maybe), offer usable electric range (likely would have meant PHEV and 30+ kms of range), or significantly better performance numbers (currently it appears it's only performance advantage is 0.1 seconds to 60mph, but need track tests to see). As it stands, all things considered equal (meaning you can actually source one), I'd just buy the Z06, enjoy the much nicer sound, the lighter weight and higher grip on dry pavement, and just have an all around more special Vette.