Betsi,

First of all, it would be a good idea to have your piano moved as little as possible. It means that if there is any chance for you to ship this piano straight from Greensboro to Boise you should do it. This way you would at least reduce the chance of it getting damaged.

Keep in mind that moving-cost-wise this might not be the cheapest option, since when moving piano alone you would probably have to pay for the minimum weight of 1000-2000 lbs (depending on the mover you hire), while moving it together with your other items will only cost you based on the actual weight of the piano.

With that being said, if your circumstances do not allow you to follow this scenario I would guess a move to Macon in inevitable. In this case your plan is the only one possible as far as I see it.

Keep in mind one thing - moving a piano is a specialty, and thats the kind of movers you need to be looking for. There are usually different piano movers for local moving or long distance moving, so make sure you verify with each company you gather quotes from if they specialize in moving pianos, and if they have the right type of equipment. Asking specific questions about piano moving wouldn't hurt (for example, ask to describe the process of moving a piano, as if out of curiosity, and never pick one that has no idea...).