I think a mix of times would be good. Starting off not long after the first game but then having an accident that sends you and a chosen companion to a different time in history. For example the founder's time where you can interact directly with them and not only learn more ancient magics during this ancient time but also influence and shape the world around you leading it to either a age of prosperity or an age of darkness depending on what you decide and how you go about the world.

Last major thing I'd like to see is perhaps a more innovative potion brewing method where you take the properties of ingredients to make new potions rather than just auto brewing known ones. Kinda like the skyrim alchemy where you experiment with the ingredients to learn more and create your own potions over time