Just measuring some models in CAD. If I stick to relatively standard scales and go for the biggest they would print (which is limited by the circumference of the airship)...

The N Class would be 1/24 - 6.7m long x 70 cm diameter (or a little less than 22' long x 28" diameter) (it would print at 1/22, but that's a pretty unusual scale)

The P Class would be 1/24 - 6.8m long x 77 cm diameter (or a little more than 22' long x 30" diameter)

The Q Class would be 1/24 - 7.4m long x 77 cm diameter (24.5' long x 30" diameter)

The R Class would be 1/32 - 6.2m long x 77 cm diameter (20' long x 30" diameter)

The Africa Schiffe would be 1/32 - 7.1m long x 77 cm diameter (23' long x 30" diameter)

The Hindenburg is tricky. It's slightly too big to print each section in one piece at 1/48, but I think I could section it to make it work, which would be 5.1m long x 86cm diameter (16.7' x 34") Otherwise, it would be 1/56 - 4.4m long x 74 cm diameter (or a little more than 14' long x 29" diameter) (1/56 is a bit of a weird scale - it's popular for wargaming, but 1/64 would probably be a more realistic 'real' scale, since it's used for Hot Wheels and S scale)

Is it wrong that I'm actually kind of tempted?

(I'm reminded of this old BBC video about a guy who built a large scale model boat in his flat:

https://www.youtube.com/watch?v=zMS6p3tIz3A )