I just thought about this the other day. Why not have the Maine-Nebraska system but with a modification? So, here it goes: each Congressional District wouldn't get 1 EV, but would get a weighed EV, with a minimum of 0.5 EV. Now in states with 3 EV, maybe divide the state into thirds (use legislative districts for example) and group them up and give each electoral district a minimum of 0.5 EV. I think this could help weed out the misrepresentation. Come up with some quota (1 EV per n number of people) or something. It's just an idea here. Thanks! 
Historically, most States that have chosen electors by district popular vote have not used congressional districts. For example, in 1789, voters in each of Delaware's 3 counties chose one elector.
Under such a scheme, Nebraska would be divided into 5 electoral districts.
