So ive bought an Watch 4 with LTE but have no dataplan for it. So the first week i thought the watch has only like 30 hours battery life without much use and always on display off. But then i saw in the battery tab that "Mobile Network" takes like 70% of all battery drain so i have turned off mobile data / mobile network from "automatic" to "off" but it did not change anything. Then i turned "Offline mode" with bluetooth and wifi on. So now i have like 300% more battery life. The problem that most apps see the "Offline mode" and say that you have to turn it off. They do not check that wifi is on. Is there a fix for that problem? I found only one or two others that have the problem but no fix.
I am very sorry to hear of the poor battery life with LTE on the Watch 4, the lack of operation with Wi-Fi/Bluetooth, and the Watch's temperature, and can understand the frustrations with these difficulties. Have you tried resetting the Watch to see if it will operate those apps with the Wi-Fi and Bluetooth? Sometimes, a restart is all that's needed to help smooth out operations on your device. For the power consumption on LTE data, there are several reasons why your Galaxy Watch may be experiencing battery drain or have decreased battery life. For example, certain apps can increase battery consumption. Keep reading to learn more about how to increase your watch's battery life. Try this guide and see if this helps your battery consumption: https://www.samsung.com/us/support/troubleshooting/TSG01003232/
Finally, for managing the temperature on your Watch, there are steps you can take as well. Give this link a try: https://www.samsung.com/us/support/answer/ANS00076952/
Please let me know if this helps.