It's really up to you want you and your family as to what your financial goals should be.
What do you/your wife want to do in:
2 years
5 years
10 years
20 years
Noting overly specific, but enough to set some income targets. Can be as simple as.
2 years - Be debt free
5 years - Scale back work, heat save 50% of income
10 years - Be self employed, pay for 1/2 of kids college
20 years - Travel, and vist grandchildren
Basically estimate how much you intended to spend on big ticket items (house, kids education) then estimate an average annual income you need to do what you want. Then figure out how much you need invested to allow for the above.
PS if the difference for me was a 2 hour ride + bus or a 30 minute drive, I'd do the drive (in an economical car), as that extra 3 hours a day is worth a lot to me with a family.