The Texas grid (ERCOT, specifically) is almost completely isolated, in order to avoid certain Federal level regulations. There's no real way for California or any other state to sell power into Texas or buy power from Texas.
Part of what happened with California is that Enron would schedule to deliver a bunch of power over transmission lines that were not rated to handle the power. When it came time to deliver the power, this forced a transmission constraint that in turn forced CAISO (CA grid operator) to buy power on the spot market (expensive) to cover the shortfall. Enron then had generation they could sell at a premium. I remember hearing stories of the ISO seeing the trade go in, recognize what was happening, and not have any legal recourse within the market's legal design.
https://thecoastnews.com/cpuc-issues-over-1-million-in-fines...
One interesting option is the option to let customers choose where they want to be on the reliability vs price scale.
Typically, in times of crisis due to undersupply, an electricity network cuts off customers (blackouts).
However, this needent happen at the district/region level. It could just as easily be implemented by your own electricity meter - effectively a breaker which opens when it detects crisis.
Crisis can be fairly easily measured from the power itself - when the supply of electricity is tight, the frequency and voltage drop.
That means a supplier could theoretically have customers choose what reliability they wanted, and set a switch on the back of their electricity meter to give them the reliability they had paid for.
The downside is that this system only works if the majority of electricity meters behave this way.
What you're really talking about is demand response. It's been around a while in both commercial and residential settings.
It doesn't really address reliability to the extent that reliability depends on investments in distribution, transmission, generation, fuel to the generators, etc. If those aren't there, it doesn't matter if the user has opted into reliable (non-interruptable) power, because the power won't reliably be at the meter to begin with.
The first California deregulated electricity market had an auction every half hour and all pricing was spot. This caused blackouts and the bankruptcy of Pacific Gas and Electric, even though it was what PG&E had lobbied for.
Today, most markets (at least PJM and CAISO) have a "day ahead" auction, and a current auction to fine-tune. Most of the market is in the day-ahead auction. This seems to have reasonable stability.
I've read that the overall effect of electricity deregulation is that prices are slightly lower, and reliability is down. Rate-of-return regulation encourages utilities to overbuild somewhat, which is not necessarily a bad thing. Beats under-building.