This blogger site is designed to forbit copying the contents so you would need to go thru the article and find the information, about 2/3 down.
For the ASW-ABS segment, you cannot leave your hand luggage on the plane. Your options are to either check the bag at CAI so it would be unloaded at ASW before the plane departs again to ABS. Then when you return from ABS-ASW, you pick up your bag(s), or to leave your hand luggage on the bus that is at Abu Simble airport waiting to transport the passengers to the site, and later from the site to the airport.
Because the writer did not want to part with their laptops and other valuables, they chose to do the ASW-ABS-ASW round trip versus booking the multi-cities as CAI-ABS-ASW
https://www.earthtrekkers.com/how-to-visit-abu-simbel-day-trip/
Right now even if you dont mind to leave your hand carry bags on the shuttle bus during the whole time you visit the site, the flight choices are extremely limited.
Your thought of waiting for the last minute sale is totally out of reality. I honestly dont understand why you are willing to spend boatloads of money on the Ponant Antarctica cruise while so skimpy on the Egypt trip, from the Nile cruise to the local guides to the fairly reasonable priced flights... The cost for an Egypt trip is probably less than 1/7 of a Ponant Austral. 
