when we have been and one of the fantasyland rides has been closed for refurb then its a small world has been open for EMH instead. Likewise Space Mountain has been closed on several of our visits and Star Tours has been open in its place. I would try asking when you arrive at the santa fe to see if it is worthwhile making the effort to get up.
I'd say there will be very little sleeping happening on Tuesday night anyways-so as it's only one morning it won't make too big difference.
Thanks for your answers everyone. Have t get my week of work finished and try to think about packing-one of those times that only hand luggage seems a bad idea(again!!!) Don't think I'll ever learn!