I decided camping at Cwm Buchan worked out best for me walking two days around the rhinogs, allowing me to enjoy a full day without worrying about finding somewhere to pitch. Arrived about 40 min before sunset. No toilets or showers but still felt like real luxury camping after only crossing bog, boulders and heather to get there. Was completely calm. Took a measurer for meths after recent discussions and used ten mil for about 450 ml. Didn't time it, but warm enough for dehydrated meal in insulated cover and small double choc mocha. Saved quite a bit of fuel over the two days compared to usual and that's with stopping for couple of brews during the day which I don't usually do apart for day walks
Now it will just be a case of not losing that measure cup.