70 litres should bring you back to mzd or atleast AthMuqam which has a branded pump.
6-7 days are enough for Neelam (without hiking) and to avoid boredom of same route, skip something from keran, kutton, sharda and visit it during return leg. Gurus can advise better but with 6-7 days, my itinerary would be;
Day 1, Isb to Kutton Jagraan Resort or AJK Tourism Keran Resort and visit Upper Neelum, would prefer Jagraan for a stay,
Day 2, Kutton or Keran to Kel, slow and steady with photography etc., stay at AJK Guest House Kel
Day 3, Kel to Shounter and back, rough track, requires 4x4 n preferably AT tires, stay at AJK Guest House Kel
Day 4, Kel to Taobatt, slow n steady with photography n experience serenity, there are stories that people of Janwai don't like tourist/photography, explore Taobatt bala n roam around, stay at Syed Shabistan Hotel
Day 5, explore a bit of Taobatt, leave Taobatt for Kel and hike to (2-2.5 hrs) to Arangkel, stay at Musk Deer Resort, expensive food but otherwise good for 1 night stay, locals of arangkel not v friendly
Day 6, explore Arrangkel n hike down to Kel n Kel to Dowariaan just for the stay at AJK Guest House Dowariaan where you can enjoy the roar of water till late night n enjoy a fresh breakfast in its front lawn
Day 7, Dowariaan to Sharda, visit Sharda Town, Univ n fort n then to Keran Resort for an lunch n an small break or so n then back to Isb, this is a hectic day.
v basic hotels n facilities in Neelum but AJK Tourism guest houses are ok and need to be booked in advance from mzd.
we might bump into each other after Ramdan as might try Deosai, Minimarg, Kamri, Burzil n Hunza