Woocommerce Optional Auto-Renew

I'm developing a store using Woocommerce. I have their plugin 'Woocommerce Subscriptions', Groups, Groups Woocommerce and Authorize.net CIM.

My client wants each order to be either a single-purchase OR able to auto-renew every 2 or 4 weeks.

Is this feasible using out-of-the-box WC Subscriptions? If not, how can I do this? A great example is Onnit's 'Auto-Renew every "x" Days' feature.

Thanks