[USER=4279]@toecheese[/USER], welcome and thanks for asking, especially as you identified your requirements.
1) Affordability as you have defined it for the long term - battery replacement from the manufacturer is prohibitively expensive (>$15KUSD), but you can peruse the ongoing efforts of some of our members doing their own replacement. e.g.,
https://myimiev.com/threads/the-aftermarket-cell-replacement-saga.4403/
and do a search for "Battery Replacement" to see more.
2) Safety is relative. I don't recall any posts on this forum of anyone being killed or seriously injured in an i-MiEV, but it has undoubtedly happened. The car handles well and is sprightly and I've escaped a number of accidents by reacting quickly and the car not letting me down.
3) Space - four adults fit ok, but the car's main attraction for me is that the rear seats fold down completely flat and the car becomes a capacious station wagon for two people.
4) Range - at 85km/hour, when new on a single charge the i-MiEV would have had a hard time achieving 120km (more like 100km), and with the now-ten-year-old+ cars it would be hard-pressed to achieve 80km. With CHAdeMO and a 15-minute stop to charge, 120km would be no problem even now. All depends on the battery State of Health. I have made many trips exceeding 250km with CHAdeMO charging - just plan on taking your time and catching up on emails or going for a walk while the car is charging. As a daily commuter, I would not expect to do more than 60km round trip.
5) Mechanical part replacement - I personally don't know as haven't needed to do anything significant in 12 years other than replace tires.
6) Extreme cold (-25°C) - living in California, this is incomprehensible to me but we do have some members in Norway and...
It's always fun to know where in the world someone is located, as we occasionally find other i-MiEV owners close to us. You might consider updating your profile (which will show your location by your username whenever you post), the procedure described here:
https://myimiev.com/threads/admin-how-to-let-us-know-where-you-are-located.5446/
For me, the biggest drawback to tinkering with the car (and all modern cars) is the need to understand the car's CANbus as they're all computers on wheels and when something goes wrong you start by looking for DTCs and go from there. There is support for this in terms of tools and apps -
https://myimiev.com/threads/testing-and-monitoring-apps-and-tools-and-scanners.4950/
and the body of knowledge on this forum is growing as people buy inoperable EVs and share their experiences.
The primary Achilles Heel of the car is failure of the Onboard Charger (OBC) which also contains the dc-dc converter to feed the 12v battery, but there is an excellent thread on repairing it.
https://myimiev.com/threads/the-troubleshooting-and-repair-for-on-board-charger-obc-thread.4079/page-70#post-50690
Perhaps others can chime in?