so much the better
That is even better. I love your sister, so if she can come too, then so much the better.
so much the worse
That is even worse. If their policy ends up crippling the working class, then so much the worse for their chances at remaining in power after the next elections.
so much the better
even better; all to the better. Please come to the picnic. If you can bring a salad, so much the better. The flowers look lovely on the shelf. It would be so much the better if you put them on the table.
so much the better (or worse)
it is better (or worse) for that reason. 1995 Guardian If you can get a tropical fruit juice…so much the better.
so much the ˈbetter/ˈworse (for somebody/something)
it is better/worse for that reason: ‘I seem to have made my curry hotter than usual.’ ‘So much the better. I love hot curries.’