Ever since the first builds of Windows 11 started becoming available back in June, there was a workaround to complete setup without internet, that was later blocked. Here's a new workaround.
Build 22000.184 RSS
Along with the Dev channel build, Microsoft has released Windows 11 Beta channel build 22000.184. Frustratingly, the issues with the Taskbar and Start menu not working are still there in some cases.