There's been alot recently on the 'cruisersforum' about cats load capability. All say performance suffers markedly with weight compared to mono's. Wetted area and slim hulls sink deeper faster with added weight.
My choise, when I get started, is trips of more than two weeks take a water maker rather than water, add rain collecting if suitable, take lots of empty plastic gerry cans which are dinghy friendly and fill a few with known clean diesel in case you pick up poor quality fuel, some with rain water for washing/cooking. Consider an extra tank for rain water if you have time to plan ahead. And stock your dinghy like a life raft. it should be the permanent home for handheld-nav+coms/watermaker/solar panel/fishing gear/dryfood then if you do bale out you will survive. Tie the life raft to it too, and all to the cat with a weak link. Standard stuff but it gets forgotten. I wish i could get past the planning stage.
_________________
Determined Prospective Sailor. House sale delays boat purchase. Experience needed - cheap crew.