My sister-in-law has virtually NO short term memory. My brother passed a couple of days ago, and I think we've decided not to bring her to the burial 10 hours away. She now occasionally asks where her husband is, even though she's been told. What do you think?
In short, no.
With dementia, imo, the person, depending on their progression is not going to benefit from things that they can not process. There is no way that I would do it, even if it were a mile away. Not only would I be concerned about her mental anguish, but the comfort level of others in attendance at a funeral.