I've been editing a project at a draft resolution of 864x486. . The final res is going to be higher.
In the video settings for a given sequence, the resolution is not editable, nor do I see way to change res in the project settings.
Is there a way to change the res of my current project?
There is no draft resolution presets in premiere. There is only the dynamic preview quality settings that can be adjusted in the source and program monitor.
You can copy all of your clips and paste them into a sequence that is the proper size, then make adjustments to individual media assets accordingly. Or you can drop your "draft sequence" in a proper format sequence and see what happens, it won't be good I'm afraid.