make ahead biscuits
To truly have the best product, mix the dry ingredients and cut in your choice of fat now, refrigerate, and hold off on adding the liquid until you're ready to bake. Make sure you're baking powder is fresh. You probably have double acting baking powder, which reacts first when mixed with a liquid, then again when subjected to heat, providing a second rise in the oven. Double-acting baking powders increases the reliability of baked products by rendering the time elapsed between mixing and baking less critical.
Alternatively, you may want to mix the dry ingredients now, chill, then cut in the fat and add the liquid right before baking.
JoyofBaking.com, one of my fav sites, states that the two stages of double acting baking powder allows you a 15-20 minutes safe window, i.e., the time before the leavening starts to lose it's oomph, before baking.
Enjoy your meal.