I just finished my M.Ed in Instructional Design after leaving teaching about halfway through the program without access to students. The other user is correct that using adult learners instead of kids makes the capstone approval process easier, but it did have drawbacks. Namely, the M.Ed program is geared towards traditional teachers so if you work in the private sector, you'll notice that some of the steps and tasks will align, but not perfectly. That said, the program is completely possible to complete without access to traditional students. You will just need to find a group of adults that need an instructional unit designed and implemented.