So, do you use bottled water, filtered, boiled? We also use playtex drop in liner bottles. Do you mix the formula in another container, like a formula dispenser, and then pour into the liners? Trying to figure out what I need to get before we head south for the holidays. Where we are going is hard to get stuff. No target, walgreens, or Walmart nearby. LO takes refrigerated bm that's warmed a bit to take the chill off and also takes room temp bm after I've pumped it. Do I need to warm the formula or just give as is?