It's always been a version of not just one camera, but two, since way back in the day. Two bodies, two lenses, one loaded with Tri-X and the other loaded with Kodachrome. Half a century ago I preferred super zooms, like the 20-35/2.8 D which BTW cost me a fortune. Ha! Ha!
Now I would opt for two modest primes.
In a perfect world, one film camera, like a FM2n and a small sensor DSLR, D2X or D500. Each with a prime, 28mm 1:2.8 (around 45mm apparent on small sensor) and 135mm 1:2.8, easily handheld and relatively fast (200mm on a small sensor.) One would still shoot fast B&W film. The digital, color RAW. (The key here is that both cameras accept both lenses, and the lenses serve different roles, I've focal lengths on each, but could be swapped if needed.)
If límited to one camera, it be a toss up: Nikonos with a 35/2.5 or D850, or Df with Voigtlander 40/2.0 Ultron.
The Nikonos would be the bulletproof one. The Nikon DSLR would be the pleasure one, the one I shoot for me.
Hope this makes sense....
Great question BTW.