EXACTLY!!! Maine and Nebraska currently use the Congressional Districts +2 method for determining Electoral Votes. No need for a Constitutional Amendment to go to this method Nationwide. Just 48 legislatures with some sense and whatever controls the DC area...
Washington DC should not have electoral votes, not being a state. The 23rd amendment gave them the number of EVs of the smallest state, but that is the opposite of what the Founders wanted. DC was supposed to be a capital district, not a state.