I'll tell you exactly what will happen; power companies will borrow a page from the book of ISPs- inasmuch as having a given amount of bandwidth available in a given area, your service slows to the point of only being able to operate on a limited basis. Just like when you become unable to stream TV and surf the internet at the same time; not to mention utilizing all your wifi doorbells, thermostats, waterheaters, bagel warmers and other nonsense. You'll need to prioritize your electrical consumption, probably leading to some form of load-sensing hardware in your main panel that shuts down non-essential circuits depending on local demand, and that will need to be installed on YOUR dime. There will be no grid upgrades, as that would cost THEM money.