Sounds like you will be trading one "record mileage" for another.
If you're willing to reduce speed and/or heat, you can easily get 70-80 mi. Not something I would recommend for a daily commute, but here's one posters one-time extreme experience, 77 mi at 28 F, average speed 35-40 mph, and still 2 bars left:
http://www.mynissanleaf.com/viewtopic.php?f=6&t=11110
If you're willing to reduce speed and/or heat, you can easily get 70-80 mi. Not something I would recommend for a daily commute, but here's one posters one-time extreme experience, 77 mi at 28 F, average speed 35-40 mph, and still 2 bars left:
http://www.mynissanleaf.com/viewtopic.php?f=6&t=11110