How should I store chilli for freezing and later defrosting?
For meat/veg in sauce recipes I anyways freeze in boxes, and often defrost in the microwave. I tend to buy boxes that are meant for microwave use but don't fuss about this (larger quantities work well in ice cream tubs). 

If you know in advance that you're going to eat it, you can defrost in the fridge. If not, aim to defrost quite slowly in the microwave and transfer to something else (e.g. Pyrex) before it gets hot. A larger container is good because it gives you room to stir, and that's a good idea when defrosting. Even the best plastic microwave containers can get very stained with hot oily tomatoes, and with others you might worry about leaching