I'm pretty sure both are doable, it's what suits you.
When I returned with DD I pumped about 1/2-1hour after most feeds for the month prior and stored that, then I was still able to pump at work so that worked for us for about 9 months after I started back at work.

One of the other girls in DD's baby buddy group is a teacher and would just leave water and solids and then feed her little guy as much as he wanted when she went to pick him up/got home.

Both worked successfully for a long time.