Many thanks for all the responses and the time you have taken to reply.
Unfortunatley for various reasons (shown below) we have cancelled the Polynesian part of our trip and extended our villa stay to cover the entire 14 nights, as it was available for the first few nights of our holiday also.
As much as we wanted to stay there, especially John, we just no longer felt right about it.
We have contacted Disney and they will arrange a full refund of the deposit.
Facts are they increased the price of the stay something which we were unaware of until we looked in the check-in online option. If that's our fault for being naive regarding the 'terms and conditions' then so be it, but the 'total price' we have on our invoice has now increased.
There are other reasons too, we cannot be 100% sure Joshua will settle there, with the first few nights the possibility his sleeping pattern will be up and down - not ideal when there are people in the next room. Whilst we will love it there I am sure we think Josh will enjoy the villa/private pool so much more. We can fully unpack at the villa without having to check-in, out more than once. The overall cost of our few nights at the Polynesian, especially with the current exchange rate is just more than we want to pay now, it's costing $568 per night there.
That's too much now we feel, especially as we are upgrading to Premium Economy both ways.
We can stay at the villa for 4 nights for the cost of 1 at the Poly.
We are convinced it's the right thing to do.
There is an element of dissapointment, but fact is the villa is lovely, probably the nicest we will have stayed in, owner's are brilliant, the Terre Verde resort looks really nice.
We will just have to encourage Josh to go out more in the evening and also try some new dining opportunities. Terre Verde is a resort in itself though with clubhouse facilities, internet cafe, health club facilities and more...I just hope the Tiki Bar is open or John will be gutted and probably drag us all off back to the Poly!
True there are negatives, but we have done it we feel for the right reasons.
Thanks again for everyone who replied, hope you don't feel you wasted your time doing so.