I always make like 10 liters of base and then freeze it in small plastic containers of 350ml each. When frozen, I take them out of the containers and shrink wrap them, this way I save much space in the freezer and always have 20+ portions of base ready.
Concerning pre-cooked chicken, I mostly prefer my chicken as tikka. On a saturday afternoon, I put 5 kg of marinated chicken (the day before) onto the grill of the baking oven until it's nicely charred on the edges, then let it cool down, cut into mouth-sized pieces and also shrink wrap them into portions (8 pcs per portion). I fit 1 kg of chicken on one baking tray, so it's 5 rounds til it's done, and you get to taste some freshly grilled tikka while you wait for the next tray :-)
The chicken goes into the microwave for 3 minutes on defrost and is ready to go into the curry at any stage. For the base, I use a simple milk pot on the stove to thaw it. Nice side effect: the base is at temperature already and is not too cold when it gets poured in the pan.