What project is bringing the most joy? Work on that one. If neither are, put them on the back burner. Unless you've got major contract issues binding you to a project time frame, take as much as you need.
Taking uploading completely out of the equation, is there a schedule that will work out best for you so you can keep up the momentum on both pieces? Alternating weekly? Biweekly?
As someone who has multiple who has multiple WIPs on the pipeline, if you don't want to work on a story, you're either going to half ass it or give up on it. So might as well work on it when you're in the proper headspace to give it the attention it's due.