You can go the screen protector route, but understand it is still not water or dust resistant, and that crack will worsen over time. In addition, the sapphire glass used on the SS series watches is quite scratch resistant, but is more brittle than the plain glass on the aluminum models. It’s quite possible it will fail before any AWX reaches the market (and who knows what features it might bring).
You can baby it along for as long as possible, but be prepared for a decision of “I now have x months before a new model is out. Will I go that long without a watch?” If the answer is no, I need a dependable watch, just replace it. You have at least 10 months before you’ll be able to consider a new model on your wrist. The S9 is an excellent watch (as is the S8 if you can find it in the model and color you want, especially with Black Friday sales less than two weeks away). You’re coming up on a good time to find a good deal, and if it were me, I’d be buying now, not hoping I make it almost a year to the next model.