They wouldn't be entitled to use communal women's toilets, even with the Haldane/Inner House judgement. Because women's human rights to privacy, dignity and safety.
They won't/can't repeal the GRA, but the best solution I have seen would be Naomi Cunningham's solution which is an amendment disapplying the GRA from the EA. Puts the GRA back in its box. Confines its operation to what most MPs thought they were agreeing to, ie allowing the people to be married or buried/cremated as a woman/man. The whole question of males counting as women for equality measures, women's book clubs etc goes away. No males, with or without certificates, in women's public facilities.