Try a different agency.
Enterprise, especially, is focused on local rentals. Even rentals from an in-town location to the airport can be complicated for Enterprise.
Alamo, National, Hertz and Avis on the other hand regularly do one-way rentals.
I'm doing a trip this week picking up in BTV (Burlington, VT) and returning a week later in BDL (Hartford, CT). I priced all the agencies. Enterprise/Alamo/National share a fleet and Alamo and National share a counter and facility in both locations.
Best I could get with National was $339 total
Enterprise wouldn't even quote it
Alamo was $130 total
And this is for probably the same actual vehicle roughly speaking.
So, it pays to shop around.