I used the project Athena replacement for the rather vague 17+ hrs claim in the Lenovo marketing slide.
That being said, the 2019 X1 Carbon got
9h 22 min of browsing in Notebookcheck's battery test without Athena certification, running on Whiskey Lake and a 51WH battery.
As for Ice Lake examples, no offense but it's an unmitigated mess. For the first time ever I actually avoided buying a cheaper ICL laptop over Renoir not because of performance (plenty on both for the user in question), but rather to avoid a nasty surprise in terms of thermals/battery life. Even with all my rants on TGL projected performance I am reasonably convinced I wouldn't have had to make the same one-sided decision in a TGL vs. Renoir situation (would have gone with better deal instead).