Assess the actual proposal before beginning activity that requires permission.
Use the intended move as a planning point
Do not assume that years of prior Canadian work remove the need for current evidence. A familiar contract cannot guarantee admission, approval or a particular authorized start date.
Record the delay, revised duties and expected completion, then compare them with the actual admission or status documents. Make a dated sequence covering the offer, planned admission or I-129 route, authorization point, travel, and any proposed first day of work. Setting the sequence backwards from the intended start date, with room for one correction cycle, is more realistic than assuming the first version will be final. Set your own checkpoint several weeks before the intended start: if the employer letter and the professional's description are not in hand, the start date should be discussed rather than assumed. If the release falls after the intended start, discuss with counsel and the employer whether the filing or entry attempt should follow the transcript rather than precede it. If authorization is needed, its route and timing depend on the actual facts; do not promise the organization a start date until those steps and the effective permission are clear. Because TN requires prearranged professional activity and bars self-employment, verify that any preliminary calls or site visits do not become productive services before admission or other authorization.