I'm in a similar position (except I have no child). I can use some advice as well.
My fiancée (who is south american) will be immigrating to the US around next Feb/March 2016. I'm deciding between UCB and Stanford (EE PhD, F15). It will take a few weeks, and probably a few months, before she can get a job. Thus, initially our only source of income will be what I get from UCB/Stanford. Which city has the cheapest salary to living cost ratio? Both universities have a salary of around $30K I believe... (that's not including summer salaries). Any help would be awesome!