Given the option of connecting or not connecting your modem/ router to a UPS, connect it. More often than not you'll keep on ticking during a power failure. I went through 9 hurricanes in 2 years and never missed a tick. Longest power outage was over 2 weeks. If you have a generator that UPS will give your generator time to get up to speed. If you don't have a generator it gives you time to go flat. Either case - put your modem/ router on UPS.
Yes that was my plan. Being on Long Island I also have gone through many hurricanes. It won't be paired with a generator but more so as something the protects my equipment and gives me time flatten positions etc.