Sounds like a great idea

Theoretically, this should work as in, if you expect the portal gun to work and the portals to lead you to the right place then I don't see any reason it should work.
However; your subconscious can play round with you and might end up making the portals lead to the wrong locations.
I'm not an experienced lucid dreamer either, but I'll try it when ever possible and tell you the results
