It definitely depends on how much fragrance you put into soap and the temp. You don't want to add fragrances to super hot soap nor should the soap melt towards burning hot lol. I add 1/2 oz pp depending on the strength of the fragrance.
Keep the bases wrapped tightly and they should keep longer than a year. On a side note, I found a bar of soap I made just experimenting. It was like almost two years since I made it and believe it or not it still lathered.