He remained in Canada, and having been trained for the Engineers and as an accomplished linguist, he was chosen by Sir
Frederick Haldimand, who became military governor of
Trois-Rivières, Quebec in 1763, to be his secretary. He resigned this position the following year and bought the
seigneury of Grandpré with part of the seigneury of Grosbois-Ouest, where he built a manor house. Both seigneurs were in
Yamachiche, Quebec. In 1771, he purchased Dumontier, next to Grosbois-Ouest; Frédérick, located behind
Pointe-du-Lac, and some lands forming part of
Rivière-du-Loup. He was appointed a
Justice of the Peace in 1765. Gugy remained loyal to the British crown during the
American Revolution, but was nonetheless harassed by various sympathizers of the cause. One of his tenants on his estate at
Rivière-du-Loup accused him of threatening to whip anyone who supported the Americans, but his name was cleared after a trial. In 1776, when the Americans were retreating, they burned some buildings on his seigneuries. In 1778, when refugees started arriving from across the border, with the marked approval of the now Governor of Canada, his old friend Sir
Frederick Haldimand, Gugy erected dwellings and a school on his seigneuries at
Yamachiche, Quebec, to house them. Gugy's reasoning was "to the end of having an eye on them", and this appealed to Haldimand who did not like the idea of the refugees intermingling with the local populace during those uncertain times. Gugy was appointed to the first
Legislative Council of Quebec at its inception in August, 1775, retaining the post until his death. In 1783, he had taken a lease out on the ironworks of Saint Maurice, but died three years later. ==Personality and death==