PowerShell open remote GUI session for UIAutomation
I'm not clear on whether it's feasible to remotely open a new interactive desktop session in which to run GUI tests that require one. I'd be interested to find out if it's doable, since problems like this frequently come up when folks try to set up CI tests of Windows GUI apps.
Alternatively, I'd propose solving this by configuring the machine where your tests run to log in as a user at boot. Then you can remotely launch your tests as that user, and make use of their open session. That's worked in the past for me when I've run into similar issues.