Using regular MiniDV footage in an HDV project merely requires that it be scaled up. I believe you will find that 221% is the number used when your project settings are checked off to scale footage to the project dimensions when placed on the sequence.
The problem is that scaling DV that much makes it look horrible in comparison. So, if you wanted to make a DVD, I would suggest that you bring the HDV into the SD project instead.
But since your project is intended for the big screen, I would not suggest decreasing the resolution of the HDV footage. So that leaves a big question. Should you use Premiere Pro to scale up the SD footage? Or, are there better programs to do that with? Is After Effects better? Should you use Photoshop to do it – one frame at a time (using an Action to do the entire directory in one command)?
That is the main issue as far as I can tell. Which is the best way to scale up the SD footage? And there are better people on the Cow to answer that than me. This assumes you have the capabilities of projecting at HD resolution. If not, back to creating the DVD and just projecting that.
Steven
Adobe Premiere Pro 1.5.1 / After Effects 6.5 Pro https://www.stevengotz.com
Learning Adobe Premiere Pro 1.5 https://www.lynda.com
Contributing Writer, PeachPit Press, Visual QuickPro Guide, Premiere Pro 1.5