If you mean the door was wide open as opposed to partially open, it would be right to say "totalmente abierta".
Else, if you simply wish to convey that the door was wide open, as in you could go in or out without hindrance, then I'd use "abierta de par en par".
Can't think of any instance where it would be correct to say "ampliamente". I think it just doesn't apply.
Also, can't think of any other suitable expression.