“Connect” doesn’t have to mean “operate as a closely coupled synchronized grid”.
Using HVDC (which is more efficient over long distances anyway), adjacent grids basically appear as just another power plant to yours (and some early HVDC connections literally consisted of a motor coupled to a generator!), and grids ought to be able to stomach the sudden outage of one.
With a worldwide grid we could make one a hundred times larger.
[0] https://en.wikipedia.org/wiki/Northeast_blackout_of_2003