So, I'm not the kinda person to bother making proper tea, pouring from one container to another etc. (hrm, a teapot would actually solve this)
OK, the plan: make tea w/o doing much work.
Pour as hot tap water as you get into a bottle, add filter tea thingies, mix a bit, leave a bit, take out filters and possibly leave in a fridge for some time.
During production of the tea we experimented with different water temperatures. It's surprising how little tea dissolved into the coldish water, even after frantic shaking. Hot water vs. boiling water also shows noticeable difference, but well... hot water method tasted good enough.
Missing (CBA to transfer), pic of "cold, hot and boiled water" tea.