If you waved a magic wand and combined them with infinite transmission for free the price in the expensive area with all the people and energy demand would barely move. (It would disproportionately rise in the cheap zones).
So any sane approach wouldn't spend money shifting the small amount of surplus power from the cheap region but spend the same money on say offshore wind feeding into the expensive zone. This is basically the pitch for zonal pricing, it tells you where demand and supply are needed. Building lots of transmission until the price is the same everywhere defeats the purpose. Building lots of offshore wind was the actual plan but most of those got rejected on bogus national security grounds.
The rejected wind farms would have doubled the entire country's generation.