The page said "Longer running notebooks and fewer idle timeouts mean you disconnect less often." I'm guessing there is a limit but it has been increased for the pro customers. In contrast on GCE you can train for 22 hours if you want.

The page says its twice the traditional Cloud.

You can work around that by saving your model and reloading.

Can you elaborate on this?

Have model training make checkpoints every five minutes. When the training gets interrupted, just restart it on a new instance from the last checkpoint. Repeat as necessary until hundreds of hours of training is completed.

Yes, exactly. To add one more detail: mount your Google Drive and save the checkpoint there.

Cloud storage bucket works better than Google Drive for both training data and checkpoints; and if you're doing training on TPUs, then I believe that you must do the data exchange via cloud storage.

OK, that also works. Just don't rely solely on the storage that comes with your notebook instance.