Sometimes we want to start something from the top but we are already too deep in the topic and cannot afford losing what we already managed to do. I personally had this situation a couple of times in my life and it is always a really hard decision. Now lets project this problem into a concrete SEO topic: changing the URL location and how this affects the rankings of the website?
John Mueller from Google already has an explanation for you. On the first of July he hosted a Google Hangout on Google+, where he answered a question from a person that renamed his sitemap XML file. John explains that changes in the URL or location of your XML sitemap will not impact you website’s ranking or the crawling/indexing process.
He adds that:
Changing the URL of your sitemap file is totally irrelevant for us, in the sense that we find the new sitemap file, we start processing the new sitemap file and we just use those URLs there. It’s not something where you have to have a history of a sitemap URL for the first things to work. So that shouldn’t have any effect at all on crawling, indexing and ranking.