Q. I will be traveling at very early hours on Erev Pesach and likely be davening Shacharis on the road. I'm a Bechor, can I just make a Siyum by myself on a Gemara I learned and eat then?
A. See question 531 that Horav Shlomo Miller’s Shlit”a ruled that if you learned the whole tractate you can join a siyum via telephone. See also similar answer in regard to zooming into a Siyum. Indeed, it is also permitted to do a Siyum all alone and eat.
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit'a