Thank you all for your comments. I went from a SP(2017) i5/8gb to a SP7 i7/16. This is only my second week with the device. There was indeed a noticeable hit to battery life. However, both times I got a new SP5 (one was a warranty replacement; had other warranty replacements but they were short-term) I noticed that the battery life the first few battery cycles was bad. Each time, I drained the battery to well under 10% once, and that seemed to improve things a lot. Went from 5-6 hours to 8+ regularly. That's from nearly three years' experience. I am in the process of doing the same for my SP7. I will let you know if I see an improvement.
Other comments on previous comments:
-I see a huge performance boost when compared to my 2017 model . I would not compare a "4 year old" desktop-class PC with an 15W ultrabook, however advanced.
-It is absolutely untrue that the pen digitizer normally craps out after two years. I am a heavy pen user and I would never buy a Surface if that were true. (This is my third.) Warranty replacement with MS has been largely painless. I've gone through that process more than once.
-The SP7 can indeed be charged using a battery pack and I second the recommendation to get one. I am (usually) highly mobile, on the train three hours a day and working mobile-y (i.e. not tied to a particular desk) most of the day. I do lots of office (PowerPoint, Excel and Word), lots and lots of PDF markup, lots of work in statistical software, some simple photo manipulation, and plenty of web browsing. Oh and a huge amount of OneNote. I bought a battery pack for my SP(2017) and found I never needed it. I imagine I'll sometimes need it for the SP7 when things return to normal.
I had a SP4 and the digitizer crapped right after the warranty ended so I one of those affected. It is easy to damage the digitizer as I know others who have had to replace their screen out of warranty. You sir have been lucky..too luck. It will catch up to you