In-depth studies petition that "the European energy system would strongly profit from exploiting the implications of these regimes for continent-scale wind generation patterns." https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5540172/ and "Such a pan-European wind power system would provide a stable output across a wide range of large-scale weather conditions" "but also requires enhanced transmission". This enhanced european grid network benefits to other forms of power production and is already planed. https://www.researchgate.net/publication/318476478_Balancing... https://www.sciencedirect.com/science/article/pii/S136403211...
There are ways to reduce loss induced by long powerlines, mainly HVDC ( https://en.wikipedia.org/wiki/High-voltage_direct_current )
All this is also true for solar, and there is even at least one megaproject: https://www.suncable.sg/
However, having said this, I would like to see a model of this with all the generation potential and costs involved, because right now we are all speculating. One can think of a multi-generation options, with wind and solar being the first and default option, battery (and other storage options) being the next option if wind and solar aren't enough, and gas being the third option if required.
Someone must have created a model like this?