I've done several trip in February on the Tonto, including a side trip to Clear Creek, and 3 season gear is fine.
But do go prepared. It does occasionally snow.
You won't encounter frozen ground. But you might encounter "rock hard" ground, especially at Phantom. Member posts are mixed, with some doing fine with sheppards crooks, but I've been happy I took easton/groundhog/sturdy stakes that could be hammered in.
And if you haven't given though to microspikes or ice trekkers, now is the time. The 1000' at the top can be treacherous (especially on Grandview). If you take them to the canyon, it's easy to leave them in the car if the weather looks promising. (But I take them regardless.)