I am in the final phase of the document preparation, so I'm quite sure that pages will not change before printing.
I noticed that, for some strange reason,
bigfoot breaks some footnotes across pages, even if there is enough normal text below the last footnotemark in the page (so that I would expect that it would have moved some normal text to the next page, thus allowing footnotetext fit within the same page).
Do you know if it is possible to locally force a single footnotetext to be unbreakable? If possible, I'd avoid to change global penalties in the preamble, because other problems may arise in other document points...