A benefits confirmation is not evidence that the immigration process is complete. Review the actual remaining decisions and authorization before relying on a US start date.
Record the milestone the letter actually establishes
The company’s willingness to fund is one fact. Vetting, eligibility, visa availability and the required residence steps are separate. Keep employment and household commitments tied to confirmed permission, and do not turn general accelerated-processing language into a guaranteed completion date for this applicant.
Compare the actual payment deadline with the revised closing and transfer dates, and contact the official process promptly if the requirement cannot be met. Address an access issue promptly through the applicable process; a contact problem does not automatically extend a deadline or guarantee a fixed residence date. A safer sequence is: confirm admissibility, pay the fee, complete vetting, make the gift only when asked, receive status, and then take tax advice on the date of U.S. residency and its Canadian consequences before disposing of property. Record the date of each submission and of each request received, and calculate a response deadline from the document itself rather than from a general recollection of how long such things take.