In the Leaflet JS library, it says:
Pans the map to a given center. Makes an animated pan if new center is not more than one screen away from the current one.
Probably a longshot, but does anyone know if there's a way to force panning more than one screen? I don't mind if there's greyed out tiles during panning.
I found there's a workaround for this:
var offset = map._getNewTopLeftPoint(latlng).subtract(map._getTopLeftPoint();
map.panBy(offset);
The developers are planning a more direct API in the future.