Yes, we are relatively lucky that it's a low grade glioma. Sorry to hear about your dad, GBM is a monster.

The oncologist told us life expectancy is around 15 years which, while ~10x better than GBM, is a pretty disappointing thing to hear when you're in your early thirties. But that number comes from looking back at people diagnosed in recent decades, so we're really hoping that new treatments will change the equation going forward.