My parents stayed in Egypt for a week on the Nile then a week in Aswan with VJV having read an article on them in the Telegraph. Of particular benefit on the Nile was VJV's use of the paddlesteamer which has individual moorings everywhere - rather than the usual necessity to deck-hop from one boat to another to get on-shore, which my mother could not have coped with at all! They have subsequently used the same company for a package to Cairo and Alexandria (including el Alamein etc)
I did have some concerns about how they would cope, as Egypt is not notorious for it's accessibility (some of the kerbs are almost too high for me, and ramps are very few and far between) - but they found the freindliness of the Egyptians and their eagerenss to please, compensated for those things they couldn't get to - and, in most cases they did manage to see things they had wanted too. Obviously going inside the pyramids at giza was impossible, and Mum struggled to get part way inside one of the tombs at the V of the K rather than visitng 3 or 4 tombs as the rest of the party did for example.
Ensure your tour company (and the airline) are as fully aware as possible of your specific needs - and obviously read the small print on the insurance policy very carefully (as you should for any trip) - but I don't see any reason why an Egyptian visit would be impossible under the circumstances. PS take a nice soft cushion for the wheelchair as roads and pathways are VERY bumpy indeed !!