I would not advise using anything freeze dried. Frozen blood worms aren't all that expensive(couple dollars more than freeze dried). Freeze dried in my opinion, is only comparable to flakes food.
A big fish around 8" would be ideal to be fed every other day. For heaters, use a 300W heater from Eheim Jager and set the appropriate temp. It should have enough power to keep it warm during the winter and it shouldn't overheat either(it shuts off when temperature is met). Eheim Jager have a really thick wall and I have never witness any fish breaking it. It may perhaps be the best heater you can get for one that is made out of glass. And if you want to spend some money on a serious heater, get something titanium(these are nearly $100 or more - for a quality titanium heater).
A big fish around 8" would be ideal to be fed every other day. For heaters, use a 300W heater from Eheim Jager and set the appropriate temp. It should have enough power to keep it warm during the winter and it shouldn't overheat either(it shuts off when temperature is met). Eheim Jager have a really thick wall and I have never witness any fish breaking it. It may perhaps be the best heater you can get for one that is made out of glass. And if you want to spend some money on a serious heater, get something titanium(these are nearly $100 or more - for a quality titanium heater).