I also subscribe to The Economist through DiscountMags. They have a price lock feature now where they will auto-renew you at the same price as the previous term. I locked in a print+digital deal a couple years ago and now it's set and forget. Typically, they renew you about 2-3 months before the old expiration, so there's no risk of missing issues and any leftover time gets added onto the new subscription period.
No affiliation, just a very satisfied customer.