The savings amounts will continually evolve as we are able to collect new data points and add them to our algorithms. The more data points we collect, the more accurate we become. In other words, we re-train the algorithm daily.
We believe that after around 10 days of collecting winter data, the data points should stabilise, and not change that much going forward (it would have learned your heating habits!). Before that you may see your savings jumping up and down a lot.