I have inquired and apparently there are two other libraries in Vermont without bathrooms. One of them, Salisbury, is slated to get a bathroom with this grant series, the other has the dubious distinction of being the last one! They do have a porta-potty in the back. Look how lovely this teeny library is.
https://wellsvillagelibrary.com/
More details about the grants awarded: https://libraries.vermont.gov/capitalprojectgrants