Daggerfall had a giant world too, but 99.9% of it was copy-pasted, unnecessary landscape that nobody ever wanted (or needed) to see. Bigger isn't better if what's there isn't compelling to begin with.
That said, I trust CD Projekt Red to get it right, and I'll be buying this on day one. Hopefully they'll be able to fill all that space with stuff worth seeing and doing.
Speak for yourself.