I can scan 35mm panorama negatives and slides using an old flatbed scanner, but the quality isn't spectacular. 15.5" in the long dimension is about as large as I can print well from those scans.
A newer flatbed scanner with the appropriate film holder is likely to be a bit better.
One could use a 4x5 or 5x7 enlarger with an appropriate film holder to make an analogue print.
Any lab that can develop 35mm film will be able to handle the development. Some won't be able to scan the results. You will need to use a lab set up to return uncut negatives.
1. Do you have a film scanner. If yes, I can describe how to scan a panorama strip.
2. In the 2004 and 2005 era, there were labs that printed Hasselblad XPan negatives into 4x10" prints. But they may have already been scanning by then rather than using a purely optical printing method.
3. The lab is developing the film. It does not matter what the frame size is on the film.
I scan my pano images with my Z7 camera - one shot no need to stitch. The total image is something like 8500x5500 pixels, which is cropped to remove the unused portion, so the final image is 8500x3000 (or whatever corresponds to the format). From that I print 36x12 inch which are pin sharp nose to print. If I want to print bigger I will uprez the image.
I get this printed at Adorama (printique) as they give you the option to print any size you want with your image in the frame. For example if you want a 60x20 print, you'll pick the 60x40 size, and it will be printed 60x20 w/in that.
They do have some pano sizes but most often not in the size I want.
I use the WideLux F7 for color and black & white film. As stated in post #4 I send out color film. I develop the black & white film and print with an enlarger, but one could use a flat bed scanner and print from scans.
I scan my 35mm panos on an Epson V600 Flatbed with two sheets of ANR glass.
One sheet down on the scanner to act as a spacer to get the film plane where it needs to be for the Epson's sharpest scans, and then another on top to hold the film flat.
Here's a 35mm pano shot on Ektar film and scanned in the manner I stated above.
My regular film strip holders (Epson V850) will easily hold a two-frame strip of 24x70+ pano negatives (two strips wide). My old glassless ones will hold three frames, I think, and take three strips. Neither one has frame divider bars; that's all done in the scanning software (Vuescan), so I can load up two or three strips, set up the frame edges and exposure, and go do something else while the scanner runs (that much film takes a few minutes at maximum resolution).
Now, I'd need a frame mask to get good prints in my D5, but that's not a big deal if you have a 3D printer -- just print one to fit the 4x5 or 6x7 negative carriers.