What does BCBSTX cover re: care out of state?

I am an ESRD patient listed with two hospitals in California and one in Texas for kidney transplant.

I am considering a move to Texas and would like to find out the insurance details first.

1: i am currently on Medicare which covers 80% of ESRD care.  So BCBSTX covers the remaining 20%?

2: In the unlikely event that California gets me a new kidney before Texas, does, BCBSTX cover care in California?