iphone was reset; watch backup not available

i had not actively backed up my phone last night and one of the usual software update runs caused a system failure. my automatic cloud backup settings are all green. today morning since the iphone is not responding to anything, the store asked me to reset iphone to factory settings. Now the Watch is not coupled with the re-setted iphone. How do I back up the watch data? I was told that there is no way you can recover data from the apple watch if it is not paired with a phone. In this case, since the iphone is factory re-set, it is not coupled with my watch. Thanks for helping me in rescuing the apple watch data somehow