Hey, man! 🙂
I am in a bit of a similar situation.
Here is the process I am working on at the moment:
1. Demuxed the DVD into a single MPEG file keeping original parameters as I did not want to lose any quality in extending it straight to a higher resolution.
2. Used Premiere Pro CC to convert to TIFF at the necessary resolution. The lowest possible seems to be 1998 x 1080. Keep in mind that the quality will suffer here. And that is normal when you extend a DVD into a higher resolution content.
3. Via OpenDCP, convert the TIFF to JPEG2000 (going to take some time) and eventually the plan is to have it in a DCP version.
So, I am in the middle of the process. Did a test run with 1 minute of content, just to make sure that it will work. Putting aside the fact that my screen is twisting the colors a bit (still watchable), things seem to be working. And of course, the quality is not too great. Hope that helps. Let me know what are you going to do 🙂