From my personal experience...

I have sailed at minimum carrying weight to get to (285). I WAS racing at about 275 combined. I could get the 16 or 18 up with that, but would use the crew on my shoulders to make it easier / quicker. Especially on the 18.

In no wind... it is harder, not easier to right. You need a breeze to get under the sails and add a bit of lift. With a breeze you can right with less weight.

If you are light, you can carry a "Righting Bucket" or canvas bag to fill with water. This is slung over your shoulder for more righting weight. These bags can carry about 150 lbs. of water.