Mirrorless seems to have advantages *except* battery life, which appears to be about 1/3 of a comparable DSLR. With prudent battery use, in-USB charging and an extra battery, this may be manageable, though. Effectively owning no lenses, that's not a factor.
I can't afford the Z6ii, so would consider the Z6 (full) based on Bert's recommendation, or Z50 (cropped). I'm leaving out the Z5, even though it's slightly cheaper and has 2 card slots, since it has a much slower no. of pics per second and I'm thinking I may need speed for wildlife on the move. The main difference is price ($1,400 for full vs. $829 for cropped, body only). Gotta say I'd lean toward saving money, but is that a mistake? Gotta admit, while I want to capture the lions, tigers and bears on my trip, I do rely more on the iPhone than a legit camera for everyday stuff. Maybe between being cheap and not a real photographer the "DX" is more my speed? I guess I don't know what I'm missing.
For full dslr I think it's between D7500 (cropped) at $729 and D750 (full) at $1,100. Both are older so the mirrorless is more attractive, if I can manage the battery thing.
The main thing is that all these models are rated well for wildlife use. Final thoughts?