Kettle size for stovetop 1.5 gallon all grain BIAB

I'm giving up on 5 gallon batches, and switching to 1.5 gallon BIAB no sparge batches on my stovetop, and mashing in my oven. I don't drink that much and I'd rather just brew a 12 pack of something experimental.

Anyways I'm not sure what size kettle to get. I really want to minimize boiloff since my batches will be so small. I also want the thing to be able to fit in my oven, which goes as low as 150f.

A 5 gallon pot seems like it would be too big, and would probably be so wide vs. the depth that I'd boiloff a ton of water.

I'm also thinking aluminum would be good because I'll want to bring to boild very quickly, and cool off quicky with a sink ice bath. I've heard these are the key advantages of aluminum over stainless.

So would a 3 gallon or 12 qt pot be good?

I've heard you want about double the batch size, so that would be a 3 gallon pot.

With that said, I made a 5 gal batch in a 10 gal pot that had 17 lbs of grain. I had to sparge about 0.5 gal water. So if want to keep it to under ~5 lbs of grain, you could probably get away with 3 gal pot. If you want to do bigger, you would need a bigger pot or you could sparge. Hope that helps.