Freezing excess BM?

Stillharbor

Ok, here's the situation.  Our frig is going bad and it's letting all the BM spoil.  I've worked really hard to build up my supply to equal LO's intake.  Most of the time I can equal what she's going to eat but occasionally I can get a little extra.  Before I just poured the day's supply in one bottle and poured what I needed into a feeding bottle.  Now I need to freeze any extra so I don't lose it.  

Can I just pour any little extra into the same bottle, over the course of the day until I get an amount LO will eat during a feeding?  It'd be like pouring 10 or 20 mL into the bottle every 3 hours until I reach the 90ml that LO is eating. Is this doable?  Or is it not good to freeze milk from different time frames?