Consider getting really "crazy"- and economical- and going iPad cellular and NO phone ? ... then using the iPad with a VOIP app and buds to cover phone & texting needs. That's what I've been doing for years with Mini 2 and will be doing for many years with this new Mini 6. If you do most of your mobile use in free-wifi zones, you can barely sip at cellular data. Cellular data-only plans are available for as little as $7/month or- the one I prefer- on-demand 2GB for 90 days for $30.
Net result: nobody I phone with can tell any difference. My "phone" rings, receives texts and gives me notifications. I can call anyone & text anyone using the free VOIP app for non-Apple people or Facetime/iMessage with Apple people. Only
ONE thing to carry around instead of two. Not using the Apple default VOIP app but another- I like free Google Voice, but there's also Talkatone, Comcast Voice, etc.
Cost result: one-time payment for this 6 plus
less than $100 PER YEAR for cellular (again, I'm usually in wifi zones most of the time so I simply add cellular when I actually need it).
iPads LAST a long time with iOS upgrades so no need to find money to buy new devices every year or two. I just rode the 2 for about 6 years and I expect this new 6 to be my "phone" + tablet for about 4-6 more.
Key cons: if you must have full functionality on Watch or CarPlay, you HAVE to have iPhone. Obviously, iPad doesn't fit in a pocket (but suit pockets, bags and purses work and I just tuck under an arm when I need it with me but am not in a suit jacket). Life won't actually end if you don't have your mobile with you at all times too
so leaving it in the car and then checking for texts and voice mail in a few hours will probably not wipe out your existence. The tremendous savings over time of cell service fails if you eat lots of cellular data and can't save big data demands for when you have free wifi access. Cameras are better in iPhone than even this new 6.
Bottom line: this works pretty well with only modest compromises IMO. In turn, there's
many thousands in cost savings this way over time. While not for everyone, this works very well for how I use mobile tech. I really look forward to my new "phone" + tablet in ONE small device.