Yes. On a cancelled subscription that is still the customer's current one, the Current Plan panel shows the cancellation reason (when reasons are enabled) and an Uncancel Subscription button. Click it, pick Select the next renewal date (today or later) and click Uncancel Subscription. The cancelled flag and date are cleared, auto-renewal is turned on, the renewal is anchored to the chosen date, and the customer receives the Subscription: Renew notification. Days that were individually cancelled during the cancellation stay cancelled – there is no single-day un-cancel. To make up for a lost delivery, skip a different upcoming day with Create new day? left ticked, which adds a fresh open date after the customer's last scheduled date.