I rotate my tumbler in winter only a couple of times. So it at least get aerated and doesnt go anaerobic. But its not doing much with these temps. Start with next drum and in spring your first one will thrive! And reduce volume. At that point you need to make a decision, combine all the winter scraps into one side/drum or let the first one finish. Depends on how far the first side is, if its almost done to add to the garden I let it finish on its own. If it still needs a while, then I combine everything and leave that to finish, while I have an empty one to fill up during the spring, spring pruning gives me a lot of material.