I think most American homes actually have panels a lot bigger than they need. 60a 24/7 is over $1000 a month. We do tend to have power hogs like swimming pools, spas, saunas and such. There is also the A/C system that sucks a lot of juice. Peak loads may get up in the 150-200a range but I don't think you really need 400a unless it is the Playboy mansion.
All that said I still average ~1.2-1.6mwh a month (all electric house including water) so I could be wrong