HBO Now stops working for 3rd-gen Apple TV in May, here are your options [update]

Update: HBO today extended the deprecation date another two weeks, so HBO Now will keep working until May 15th and HBO Go will continue for a few more months.
The HBO Now app is ending support for the third-generation Apple TV on May 15 (originally scheduled for April 30). HBO Go will be discontinued at a later date. The apps will no longer work when that time comes; a banner is now visible in the HBO app on the older Apple TV boxes explaining the impending removal.
Although the third-gen Apple