Susan,
I am gr.gr. grandaughter of John Dion and Victorine Cote. In 1881, John and Victorine had a daughter named Irma Victoria Dion. Victorine Dion died in childbirth in 1887. At that time John Dion moved to New Bedford Mass, area with the child born in 1887, named of all things Victorine. The young Victorine lived to be 2 months old.
My gr. grandmother Irma is very difficult to find in census records because here birth in Dec 1881 misses all census documents until 1900 after John Dion left Brattleboro. My gr.grandmother Irma, lived with her older brother Adonias (called Idomies on some census) and his wife Jessie until she married my gr. grandfather Joseph Fontaine. This can be verified in the 1900 census for Brattleboro. Adonias and Jessie moved to Pittsfield MA shortly thereafter. Adonias and Jessie Dion never had children. They adopted a girl named Veronica who was raised as their own. Veronica died a few years ago and I never was able to meet her. I heard that I had a very old Aunt in Pittsfield for many years, but never knew her personally. So I hope this helps about the Idomies question.
In all of my research about this line of the family, it seems that there were few descendants other than your line from Eudore. The other brothers did not have children as far as I can tell.
If you have any photos of your Dion line, I would love to share them. I have some photos of Irma Dion. I was unable to get photos from Veronica Dion who died a few years ago. I tried, but the people who controlled her estate did not know of any family and destroyed them before I could contact them.
Michelle