EG: My process is pretty straightforward. I drop off film at the lab and they give me pretty big scans of the entire shoot in about 3 days. That goes into the computer and its just like a digital shoot at that point. If the client needs a bigger file, then I may do additional high res scans of the final files.
You have to communicate what this will look like to the client. I live in NYC, so I can run to the lab pretty much the same day and in 2-3 days have decent scans ready to go. But your location or post processing process may differ. I find that 2-3 days is not really a deal breaker for most situations.