Dear bmiers:
Thanks for your help and advice - this is what we have done:
We were booked on the 3.00pm non-stop flight from ORD - LAS arriving at 4.55pm giving little margin for error to get to the 7.30pm concert if the flight was delayed. The earlier non-stop flight 8.29am - 10.24am would have meant getting up a bit too early and arriving when we may not be able to check into our hotel (and probably falling asleep at the concert!)
We have now re-booked connecting flights ORD - PHX - LAS leaving 10.35am arriving 2.24pm. Will need to get tickets re-issued but no problems.
We have kept our original bookings at the Alladdin ($68 per night) - (Caesars Palace wanted $200 per night). Booked tickets for the show direct through Ticketmaster.
Everyone happy!
If Elton is reading this - how about meeting for an after show drink!
Thanks to everyone for your help and advice.
Nigel.