I would fly WestJet. They fly to st Maarten all year several times a week where as airtransat only flies there once a week & only mid December to around mid April.
Airtransat dropped us off in January 3 years ago & 3 days later sent email cancelling our flight home in February. We scrambled to get WestJet flight at $900 to come home. It took a year & a lot of arguing to get reimbursed. We weren't impressed to say the least.