A friend of mine has done Luxor several times alone - usually a weeks cruise then a week at the Movenpick on Crocodile Island. She loves it.
Being on the cruise makes it better if you are alone as you get to see the same faces and you never know, someone may be doing the same itinerary as you so you will not be alone as such.
My friend tends to eat either at the hotel in the evening or - goes out around the shops around 6pm and then eats before 8pm and goes back to the hotel to read and relax.
Shopping and walking around is not too bad although you may get asked where your husband is - if they see you on your own a lot. Tell them he is joining you in a couple of days......
Cyprus100