That's not even necessary. Depending on the design, it's possible to apply transfers in sections with multiple pressings. Check out Proworld's video 'Applying Oversize Transfers' here: Instructional Videos - Pro World
You are right - it's very much design specific and depends on what type of printing method is going to be used.
If the design doesn't require seamless and consistent coverage of the whole t-shirt with colour or graphics I suppose it could be done with multiple pressings.
It's tricky to do with dye-sub as the chance of already pressed part of the design bleeding/ ghosting/discolorating while pressing the rest of the transfer is quite high.
The technique shown in the instuctional video works well with what I guess is a plastisol transfer, but it wouldn't work very well (if at all) with dye-sub transfer and it would be tricky to apply all-over print this way (sleeves, front, back and all).