Help with Cowarra

We are building on 1,100 sqm just outside Wauchope and this is the one we keep coming back to. It is a wide design so it suits the block. Two questions for anyone who has lived in something like this. Is 371 sqm on one level too much house to heat and cool? And would you move any of the four bedrooms around? Happy to hear the bad news now rather than in a year.