wow... you do realize that you will be seriously blowing up pixels.
Start with a 1920 timeline and place your footage in it. It will 'float" in the enlarged timeline.
You will be able to resize the video and see how it looks by rendering it through AME by picking h.264 blu-ray.
good luck. Too bad you didn't shoot in the final size to begin with
Yes, you can definitely do what you're thinking of doing. You should probably select a sequence preset that closely resembles your delivery requirements (you didn't mention the frame rate of your footage or of your delivery file), and then click on the Settings tab in the New Sequence dialog and setting the Editing Mode to Custom. That way, you can easily change any parameters that don't match your delivery requirements. A 1920x1080 square pixel sequence at your necessary frame rate should suffice.
One thing to note is that in Premiere Pro, there is no specific "project" setting--a project is simply a container for sequences, so you can have multiple sequences with all sorts of different combinations of settings.
Anyway, once you've got your sequence established (you might save a preset if this is something you'll be doing again), you can plop in your footage/graphics/etc. and position them where they need to be. I do similar things for digital signage myself, so it's a totally workable situation.
Not necessary; the OP is not planning on blowing up the video.
Thanks, that solves the issue. Yes, I am not intending on blowing up the video. This was my solution to that potential problem. I was able to use 6 standard def video clips in one HD clip and still had room for titles, etc.