You had to open a can of worms, didn't you :-)
Actually, the answer is that you will definitely have to do your own prints to see if they match what you are attempting to achieve.
To make a more complex issue somewhat simplified, digital is resolution limited, film is grain limited. What this means is that as you exceed 16x24 enlargement size with 35mm color film prints, you yield quality and aesthetic value to grain. Pro level digital sensors have so little noise that there is nearly unlimited enlargement potential with one very BIG caveat: You absolutely must keep the field of view small enough to not challenge resolution. There are two ways to do this. Shoot a narrow field of view (portrait, a few people, a horse, dog, cat, etc.,) or shoot several overlapping images and stitch them in software so that you maintain sufficient resolution to allow interpolation algorithms to do their jobs properly.
The EOS-1DS will make a dynamite 16x24 landscape print equal to any 35mm film capture. The EOS-10D is significantly below the usable resolution level of 35mm fine grain color film or transparency. With smaller fields of view, you can print beautiful 100" enlargements with the 10D. But, if you push it with distant and detailed landscapes, at 16x24 you will "probably" not be as happy as with 35mm color film.
Take the same shot in four frames and overlap them about 30 percent and stitch them in software (it's easy and works very well as long as the subjet doesn't move) and you have a landscape shot far better than you could get with 35mm color film for enlargement purposes.
Best regards,
Lin