Since it won't cost any extra miles, I would pick one other country to visit, say DXB, and make CAI your stopover. Domestic flights and trains are reasonable in Egypt.

If you have time, use the award ticket to visit a place in the vicinity you probably will never travel back to.

If you do pick DXB, you can travel on SQ between CAI-DXB, albeit on an older aircraft.

But that's just me and my insatiable urge to visit every country on the map.