Closing transfers the business but does not confer permission to work in the United States. Owning the resort and running it personally are separate questions.
Ownership and work authorization are different events
Hypothetical example: A commercial closing can proceed on the parties' own schedule, and Canadians may buy United States businesses without any immigration process. What the closing does not do is authorize the buyers to be present performing the work of managing the property. Many purchasers bridge the gap by retaining the seller or an existing manager to operate the business for a defined period, or by keeping the operation running with existing staff while the application proceeds. That arrangement should be documented, both because it protects the business and because it explains the period between closing and arrival. Beginning to work personally at the resort while a decision is pending creates a problem that no commercial deadline justifies.
Tie the immigration sequence to contractual deadlines, escrow release and the point when the investor must begin directing operations. Hypothetical example: A robotics-tutoring studio has a lease starting in two months and equipment on order. The investor must decide which costs can safely be committed now and which can be protected by an appropriate contingency. Waiting until every risk disappears may leave too little evidence of commitment; spending without a plan may expose funds unnecessarily.
Keep the commercial and immigration calendars together. A missed contingency deadline can change whether a payment remains protected or has become an irrevocable business expense.