You actually have a few options to get to the Studios from Epcot.
From the FRONT entrance at Epcot, there is a direct bus to the Studios.
There is also the International Gateway entrance at Epcot (in between UK and France in World Showcase). You can exit there and take a boat or walk to the Studios.
So a lot would depend on where you are inside Epcot when you need to leave.
There is also the International Gateway entrance at Epcot (in between UK and France in World Showcase). You can exit there and take a boat or walk to the Studios.
It takes about 30 minutes from the IG to DHS plus boat waiting time. The boat is slow and it stops at Yacht Club/Beach Club, Swan/Dolphin, and the Boardwalk before heading to the Studios.
It's a mile and a quarter walk from the IG exit to DHS entrance.
The boat is a nice relaxing air conditioned ride, probably a min of 30 minutes at best if you don't have to wait for the boat. At worst maybe another 20 -25 min.
I would think boat or walking would be the preferred way to get to DHS, plus you'll get to see a little more of Disney that you might not have seen before.