Back in late June, a roadmap revealed by HTC "insider" Llabtoofer hinted at the possibility that HTC would combine Android 4.4.3 and Android 4.4.4 in one last update before Android L makes its way to the device. According to that roadmap. the HTC One (M8) is supposed to be receiving Android L in the October through December time period.
Those in Canada with the HTC One (M8) should keep their eyes open for the Android 4.4.3 update. When it comes, make sure you have a Wi-Fi connection before you download it, so you can save your precious data for really important things, like uploading pictures of your cat to Instagram.