Even if Texas were fully integrated with the National grids, there was not enough excess capacity to meet the Texas' increased needs in addition to every other affected States' demand. Heck, it would habe magnified the severity of the problem. All the Mexico connections were shut down because they had their own issues. We could very well have ended up with a cascading grid failure on a National scale, which would have helped nobody.

This is not just a Texas problem, and the fact it stayed isolated to Texas and didn't effect other States' adversely was entirely an artifact of Texas' independent grid.