This was a key reason Napoleon failed to set up a North American empire:
The Napoleon did not have enough resources and sufficient power to defend its vast territory that had grown so large. The Napoleon forces opted to sell Louisiana's French territory, including current, Lowa, New Mexico, Northern Texas, Minnesota, Missouri, Kansas, Montana, Oklahoma, North Dakota, Nebraska, and southern parts Manitoba, City of New Orleans, Wyoming, among others.
The French colonies were to face the British in 1803, who combined their forces with colonists of British North America, and the plan was to overthrow the Napoleon French forces in the United States. An option to sell the land was more lucrative than to enter into a war that the French predicted a loss.
Egan, C. L. (1969). The United States, France, and West Florida, 1803-1807. The Florida Historical Quarterly, 47(3), 227-252.