iPhone 15 Pro Max.
Replying here after 1 Month of use - after the 17.0.3 update my phone is fine. It's also fine with iOS 17.1 - I have been using the phone normally, and have not seen any unusual heating, warming, or battery use anymore.
In fact battery life is stellar and I usually go to bed at night with around 50% battery remaining.
In hindsight I believe there was a bug that was fixed with 17.0.3 (and also in subsequent OS releases)
Also add the fact that when we set up a new iPhone from iCloud backup, it works very hard downloading and installing all apps from the app store, indexing all files for spotlight, indexing all photos, running photo recognition on my roughly 20,000 photos, and so on - it does a lot of stuff in the beginning.
So give it 1-2 days, upgrade to 17.1 if you haven't, and then see.
Restoring from backup is an awkward phase of high CPU use for the first few days, especially if you're like me and always sleep with airplane mode on, meaning the phone can't do most of its work at night either.