It's expected that Apple will go 64-bit exclusive with the iOS 11 rollout later this 2017, thereby ending OS support for the iPhone 5 and iPhone 5C. In such an event, there is life after iOS 11 for both handsets courtesy of the now expanded 32-bit jailbreaking.
Gizmodo has earlier reported that beginning with the release of iOS 10.3.2, now on public beta 2, iPhone 5 and 5C users can no longer access official firmware support from Apple. Why the decision was not explained but the report can only speculate of internal hardware limitations or the tech giant simply want users to finally retire the handsets and jump to the later iPhones.
However, the same report was updated and due clarification was made that the mid-cycle OS support stoppage is not happening. Both the iPhone 5 and 5C will still get iOS 10.3.2 but certainly not iOS 11. The latter for sure is only for 64-bit devices.
So end is inevitable to happen soon for the iPhone 5 and 5C? Not necessarily if one is willing to jailbreak and go through the process of downgrading from a firmware version then taking the jailbreak route, which for the 5 and 5C is limited to iOS 9.x.
The solution pointed to by iDownloadBlog.com is the iDeviceReRestore 1.0.1 that is now ready to download and use for MacOS and Linux (availability for Windows is yet to be announced). According to the iDB report, the solution will permit the downgrading or upgrading from a firmware of origin going to iOS 9.x and then a device is good to jailbreak.
The re-store bug has been tested to work on numerous firmware versions - from iOS 6, 8, 9 and 10 - so theoretically iDeviceReRestore will help iPhone 5 and 5C users in case they decide to get out of the official iOS ecosystem once iOS 11 is deployed.
The option for them is slide down from iOS 10.x and head to iOS 9.x. It's important to note that jailbreak users need to have the saved blobs for the destination firmware so if one plans to jailbreak and end up with iOS 9.3.4, for instance, the process can only completed with saved blobs on 9.3.4.
Having all the necessary requirements then the iPhone 5 or 5C can now be cracked and jailbreak fans can choose between Pangu9 and Home Depot. The former will allow jailbreaking from iOS 9.2-9.3.3 while the latter spans from 9.1 to 9.3.4.
Whichever the choice is, it's quite that iOS 11 will not spell the end for iPhone 5 and 5C, and thanks to iDeviceReRestore 1.0.1, which swings the door wide-open for 32-bit jailbreaking, for that.