I think that with that kind of driving, and the fact that you seem like a guy who likes to keep your car as long as you can..... Time is your enemy. Odds are that you will buy a used Leaf. The car will have an already-deteriorating battery in it. If you only drive 5000 miles per year, time will deteriorate the battery faster than you build up the miles. Then you are in a situation of having to replace batteries ($5k), and need to determine of what did it cost you PER MILE. If you got a new Leaf, then the equation may be better.
I have a low mileage 2001 Honda Odyssey minivan with only 60k miles. We only use it for around the neighborhood for shopping, to carry all the family together, and to haul plywood and crap from Home Depot... I have no plans, in the next 10 years or more, to get rid of it because it serves its short-trip function perfectly. Gas cost per year is not an issue. Insurance cost per year is nothing due to age of vehicle and low miles driven. Maintenance is not an issue... One oil change per year, tires last 10 years, and no repairs except maintenance. --- I would not own a Leaf for that purpose because in 16 years of ownership and 60K miles, I would now be on my 3rd of 4th Leaf battery (at $5,000 a pop). Not a good long term investment.
I Think that the best use of a Leaf or any EV is to use it as much as possible, even a 24-hour running taxi, which will use the battery potential to its highest.