The summary of the proposition as it appeared on the general election ballot: Do you want Maine to expand Medicaid to provide healthcare coverage for qualified adults under age 65 with incomes at or below 138% of the federal poverty level, which in 2017 means $16,643 for a single person and $22,412 for a family of two?
Information on the language of the proposition is from the Official Voter Information Guide issued by the Maine Secretary of State: http://www.maine.gov/sos/cec/elec/upcoming/citizensguide2017.pdf
A total of 405 votes were cast by citizens abroad; 358 in favor and 47 against. The state of Maine does not tabulate these votes by county.
Source for Popular Vote data: Maine Bureau of Corporations, Elections & Commissions. November 7, 2017 - Referendum Election, Maine Bureau of Corporations, Elections & Commissions (http://www.maine.gov/sos/cec/elec/results/2017/results1117.xlsx) (accessed 18 Dec 2017)