Siince I'm (going to be) new to driving an EV, maybe I'm overly concerned about charging the i-Pace up to 100%. Maybe I just need to get the feel of "driving on a full tank" out of me and then decide on a home based fast charging system
I charge to 90% every day. That's the default setting on a Tesla. People say to charge to less to prolong the battery etc. but the evidence on Tesla has been that it makes very little difference, and isn't worth even bothering to think/fret about. If you are going to be leaving the car parked for month then plug-in and set-to-50% is probably a good idea.
If charge to 100% then don't leave it like that, plan to drive "soon". That said, on 240V it takes 1.5h to get from 90% to 100%, so its sitting "almost full" for a fair bit of time, even if you then leave immediately,. The advice I have had, and heed, is "don't stress about it". if I charged to 100% and then had no reason to drive I would shed some miles promptly. 1% is 2 miles-ish, so driving 10 - 20 miles will get it down to 95% - 90% ... but if plans changed and I would not be leaving for 3 or 4 hours I would just leave it alone.
Similarly don't leave it below 10%. If I get home below 20% I charge immediately (rather than waiting for off-peak scheduled charging). But that makes sense anyway ... I might have to go out again ...
I'm not sure that i-Pace is 100% when fully charged, there is some talk of it having a top-buffer, so the Tesla 90% thing may be moot. If Jag tell you to charge to 100% then its probably actually only 90%-of-real and therefore fine.
My real-world range is 220 miles. I "mentally" leave 10% / 20 miles "in the tank" for contingency. Road closed / detour, overshot the exit ramp Doh!, or "Can you just pick up X from Y pls" phone call
so 90% less 20 miles is 178 miles. If my journey is more than 160 miles I charge to 100% (and then I have 200 miles range plus 20 miles contingency)
Important point is that you start each day with a full tank (be that 90% or whatever). So I have my 90% range, 178 miles, available every day 7/365. I go further than that about twice a month, and for that I do some Prep (unless it is a familiar route, with known charger-locations) and usually start out with 100% charge. (I also pre-condition the Climate in the car using Shore-power, so that AirCon / Heater isn't using battery when the journey starts, but its probably a very small point. Flat out AirCon uses equivalent of 4 MPH, so if doing 75-80 MPH its irrelevant, if crawling at 2MPH its more relevant, but still 220 miles / 4 MPH = 55 hours runtime for AirCon when in slow traffic

)
In Winter (my average-worst-case is February, temperature -5C to 0C) range is about 20% less. (That ALSO applies to torrential rain)
home based fast charging system
Not sure you need "fast charging" per se, but I'm not very familiar with USA systems. As I understand it you would have a 240V dedicated charger, and over here with 240V and a 7kW charger I get 22 MPH.
To need an all night to charge you would need to come home "empty", and be charging to 100% ... which rarely happens in practice of course, so for, say, 100 mile top-up you would need 100 miles / 22 MPH = 4.5 hours
Does anybody really know if the i-Pace will come with an adapter so I can use Tesla's supercharging network?
Seems very unlikely to me (although i have NO idea why no-one has done a deal with Tesla to use Superchargers). The CCS rollout is coming ...