Hello all, new workflow will have my saving a completed and edited wedding to a single HD video file. This would allow me to delete all my "working files" and raw files. I am ok with saving a folder of 10-20 gigs, compared to 50-70 gigs. So the question is this:

Is there an "ideal" format to save this file for future burning?

Ideally, I would like to have the option of simply burning a Blu ray and/or DVD from this single file should a replacement or copy be needed down the road.

For Blu-ray, you need to save the BDMV & CERTIFICATE folders.
For DVD, your best bet is to create an ISO file and save that.

With these saved, you can later burn either format.

Is there an "ideal" format to save this file for future burning?

Ideally, I would like to have the option of simply burning a Blu ray and/or DVD from this single file should a replacement or copy be needed down the road.

The two formats are really different; a single file for both is unrealistic. You're going to have to save two different files, one for BD, one for DVD. Sorry.

It will be easiest to save 3 folders: the DVD ISO, the blu-ray info, and, for me, mp4s for computer/online.

You could save a single master file in either Apple ProRes or Avid DNxHD. That file becomes your master for authoring DVD and Blu-Ray. You can then save disk images from your DVD and Blu_Ray authoring programs.