Where we currently live is convenient for the kids, as they can walk to school but apart from that there is nothing else that we need to be in town for.
Depending on the age of your kids this could be a big thing for your wife, having to put them on the bus, it's not really a big deal but these things are big steps for the Mums at time when it comes to their precious little kids. But considering you both like the place that's for sale well that's a good indication, maybe she just needs a bit more time to think about it and get her head around the idea.
I think sometimes being in a more rural setting can be safer, less people wandering around etc.
We lived 15km from a small town when our kids were younger, it was great, the neighbours houses were only just visible and they were nice and friendly, the kids knew they could go there if there was ever a problem (my Husband worked away and they caught the bus from outside the property (only 7.5acres, neighbours were like 10ac, 15ac and 100ac so emergency scenario was if I wasn't home and didn't get home in a certain time when they got home from school etc).
Anyway only reason we did move to a bigger place was for schooling as they got older, small town only had high school to yr10 and not many students, didn't want an hour bus trip for kids to go to high school to neighbouring city (like a lot of people from town did). There wasn't much keeping us on the rural property apart from lifestyle. It is more work keeping the (bush block) bush clear, firebreaks each year, cutting and splitting wood for the winter etc.
I think it's a great opportunity while your kids are young, it will certainly benefit them, our kids (now 10 and 12) have fond memories of that place. Besides if it doesn't work out you can always sell and move back to the big smoke (or do so when the kids are older if it suits you better then...maybe if finances are great you can keep the rural place for retirement).
We still have our rural property, we've been able to rent it out which is good, it's a bit of a burden with such a big mortgage though. Circumstances of Hubby losing his job saw us having to move to Kalgoorlie last year, it's pretty good, not a big place so we like it here. I really enjoy the convenience of kids being able to walk to school (particularly as I have to work as well) but it's just as convenient if they can get on a bus providing htey don't have to spend excessive time travelling to school.....like more than half an hour.
Anyway from a womans perspective sometimes I'm against ideas but end up warming to them, so discuss further and maybe give her time to think about it, just don't push the point.