I do all my pixel art with mouse. It is, however, usually 16x16 or 32x32 canvasses, or some small multiple of 16 (16x48 platform, for example). Larger wholes tend simply to be constructs of these smaller tiles (a terrain tileset for example). Occasionally something bit larger might be necessary, like perhaps a 64x96 house front, but that too is mouse work. When you zoom in enough to the canvas when drawing, it doesn't really matter what your tool is. The real test comes when you bring the sprite in to the project and see how it fits with the rest.
(My approach is not the best though. If you're drawing pixelart for a 2D game project, you probably should've done some sketches first to figure out a consistent style, and colors. But since I just develop solo, nobody's getting bothered by that.)