TD status does not authorize employment, and managing a rental business from a laptop in the United States is work even if the chalets and the guests are in Québec. The activity needs its own review before it continues from U.S. soil.
Locate the work where the person is sitting
Hypothetical example: the graphic designer's husband manages four short-term rental chalets around Stoneham-et-Tewkesbury through listing platforms and a local cleaning contractor. He assumes that because the properties, guests and income are Canadian, nothing changes when he accompanies her to Vermont in TD status. The status question does not turn on where the revenue arises but on the fact that he would be performing work while physically present in the United States without employment authorization, which TD does not carry.
Passive ownership with a Québec property manager running everything is a different fact pattern from daily guest messaging and pricing decisions, and the line between the two should be drawn with counsel before departure, not after. TD children may study; nobody in TD status may work. If his role is genuinely active, options include restructuring management, limiting his activity while in the United States, or seeking a route of his own, each with different evidence.