> I want to offer them something to subscribe now if possible but do not want to charge them until sports starts back up.
App Review seems to want a free trial to be done under the Autorenewable 'introductory offer' free trial rather than a do it yourself approach. I believe they are all limited to fixed time periods.
You can lower your subscription price and then raise it when the 'season' starts. I don't think you can lower your price to 'free' though.
You can remove the autorenewable subscription from sale so that no one signs up.
It's a kludge, but you can launch your app with multiple IAPs each of which includes a free trial for a selected time period of 3 Days to 1 Year - let's say you pick 3 months. Have only one of those IAPs be 'cleared for sale'. If after 3 months you want to extend the free offer, then mark the second IAP as cleared for sale and tell your users to select the new, free period IAP and ignore the old one. To prevent them from being charged, raise the price of the first one so it does not automatically autorenew and remove it from sale at the same time.
I am not sure if you're able to change the free trial duration still, I assume you can. If you can why not extend the free trial till August or September, i.e. 3-4 month free trial? This would let people get to use the app, and if sports to slowly begin in July/August give users a chance to try the app then?