We're moving to a new subdivision with our 100lb dog?

We have a 100 lb golden retriever and moving to a new subdivision. It will be a few more months before we have a back deck, and gr. Our front yard is still mud, no sod. Im looking for suggestions with him for going outside to do his business. We plan to take him for walks anyways, however he's kind of an odd boy. He doesn't go to the washroom on walks, he's always waited and come home to do his business in private, even on an hour long walk. I've looked into the potty patch but it looks cheaply made and not worth the money. We will have a gravel driveway but i don't know how to get him to use that either.