Great question! As you mentioned, there are a few ways you could set this up.
My recommendation would be to create one template task that contains subtasks for all of the steps you take for a blog post (i.e. Decide on topic, write first draft, edit, find hero image, etc.). Then you can copy that template task for each week and schedule it on the calendar or timeline. You can see an example of a similar recommendation in the Editorial Calendar Guide post here.
This would require you to make ~50 copies of the task, but this shouldn’t take too long with the “Copy Task” feature, and then all of your steps would be built out for each post and you would have a master calendar to use along the way. Do you think this might work?