I’m going from memory here since I’m on mobile, but the width is 100% and the height is auto (not explicitly set). It’s managed in CSS, so with the right syntax and targeting, you should be able to override it. You should be able to check with your browser developer tools, but as is implied by the name, the truncate class prevents text-wrapping, applies an ellipsis, and hides the overflow.
The title truncation is a dashboard setting: Title Truncation Dashboard Setting