Not sure if you would like KDE, but that has something called activities. These are basically desktop sessions you can save. So for example you could have several terminals open, a few documents, maybe an IDE...whatever you happen to have open.
Then before you restart, you can simply save that activity. You can create as many activities as you like. You can even have the same application open in one activity that has certain files open, and have the same app in another activity with different files (imagine different projects for example).
Hopefully I haven't misunderstood your question, but to make sure do a search for KDE activities. It can be a little hard to find the right information, so if you have trouble post back here.
Best way to learn is to simply open up a whole bunch of stuff and save that as an activity. You should be able to find how to do that easily enough. Then close everything (or modify what u have) by opening new apps, or new files in the apps. Then save that as another activity.
Now you can load each activity at will, even after restarting your PC. You can have separate widgets, different virtual screens, etc. Give it a try and you should quickly determine if its what you need.
NOTE: I dont think the gnome activities are the same, as far as I know this kind of power is only achievable via the latest KDE you get with Debian 8 Jessie.