I double bread recipes all the time. Are you mixing by hand or in a machine? By hand, it will be a large amount of dough to handle; otherwise, you’ll need a large mixer capacity. Agreed, that timing may need adjustment, but often that is the case due to ambient temperature. Also consider if you have enough room in your oven. I find when baking 4 loaves I need to heat the oven to a higher temperature to account for the heat loss of adding all four pans to the oven, plus the cooling that takes place by having 4 vs. 2 loaves in the oven. I’m still experimenting, but I’m going to start removing the stone after baking about 1/2 way through because if I place 4 loaves on the stone, I think the benefit is eventually lost (reason I’m investigating is the bottom crusts aren’t as dark and browned when I bake 4 loaves vs. 1 or 2).
If for some reason you can’t fit all of the loaves in the oven, you will want to adjust proofing time for the ones you don’t bake first—place these in fridge.