How far in advance can you make cinnamon buns, from scratch, without cooking them?

According to Amanda, you can make the dough the day before and keep it in the fridge for the first proof. The next morning -- shape the dough and let it do the second rise before baking. Hope that helps!

So I can assemble up to the point of baking and then keep in the oven until ready to bake? No need to let it come to room temp or anything?

You can very safely make the dough the day or the night before, and bake them when you're ready the next day!