Did 16 nights (plus two over night flights) with HLO - and no washing. 18x underwear, 18x shirts, jeans, casual trousers, shorts, bathers, bike shorts, exercise top, walking boots, runners, thongs, 500g ground coffee, aero-press, chargers, tablet.
Wore walking boots (heavy & bulky), one warm jacket (flying out of winter, into summer), kindle, phone, wallets in jacket, almost all clothes in one wheel-aboard carry on, plus miscellaneous chargers, etc. Runners, thongs, electronics, coffee, fragile in small backpack. Was banking on the wheeled carry on being carry-on and the small back pack being the additional personal item (wouldn't have worked with JQ), but would have checked the wheel-on if challenged as nothing fragile / valuable in it.
Worked a treat - the ability to walk straight through customs when arriving in US, not collect your checked bag and re-check for your domestic leg, and the ability to jump straight on the bus to the rental cars at your final destination.
Only downside - when I arrived back in Melbourne I was kerbside 10 minutes after getting to the gate, and 15 minutes after touchdown. My driver wasn't there yet, because I was too quick (even though I'd texted when I arrived and told him I'd be there soon). Just about to do 23 nights (plus 2 nights travelling) - may need to take some detergent this time to do some washing, but definitely not checking luggage.