Very sorry to hear about your diagnosis.
In some cross-sectional studies, median bulbar onset ALS survival is 26 months past diagnosis, which more than doubles if progression is limited to the bulbar region for 20+ months ("isolated bulbar palsy," with which being female and a more upper motor neuron presentation is more often associated) but as Nikki says, nothing is written in stone. The longer you have purely bulbar symptoms, probably the longer your survival, but survival is also changing for ALS generally.
Besides Nuedexta, Riluzole, Radicava, and Relyvrio are all treatment options to discuss along with many other strategies
to extend the time worth living. And we would expect these to extend survival as a whole.
You will be able to "see" your grandchildren, even if virtually, as they grow, and they will grow understanding that you will communicate with them differently -- using a computerized voice (that are pretty good these days, and they might enjoy hearing you switch to different accents, etc.), texting, signing, dancing, whatever you come up with for however long. And these sessions can be recorded so they do not forget. You can dictate letters to them and send them whimsical gifts. You can watch them learn, play, and travel and you can share your local plants, animals, destinations, with them. Etc. While your limbs permit, you could knit/cook/craft/compose something for them and ask their parents to record its receipt.
You don't know what time is left -- few of us do -- but you can find lots of ways to make it count.