FWIW I disabled "Allow network connectivity during connected-standby" in group policy and it seems to be better (fingers-crossed).
Apparently I'd set that to "enabled" last year when trying to deal with the wifi flakiness after wakeup. However setting it to disabled now, I am not getting the flakiness so far, so maybe a software update fixed that problem. (Again, fingers crossed).
Two days and so far it's worked. Drops 1% power overnight (compared to 8% per hour pre-change), and connects straight back to wifi upon wakeup.
Note hibernation is still disabled. This is just sleep. And I didn't hack anything AFAIK to disable the connected-standby that Dell/Windows forces. So, pretty happy! (Of course, was looking forward to trying out a Mac, but oh well).
The following sleep states are available on this system:
Standby (S0 Low Power Idle) Network Disconnected
The following sleep states are not available on this system:
Standby (S1)
The system firmware does not support this standby state.
This standby state is disabled when S0 low power idle is supported.
Standby (S2)
The system firmware does not support this standby state.
This standby state is disabled when S0 low power idle is supported.
Standby (S3)
This standby state is disabled when S0 low power idle is supported.
Hibernate
Hibernation has not been enabled.
Hybrid Sleep
Standby (S3) is not available.
Hibernation is not available.
The hypervisor does not support this standby state.
Fast Startup
Hibernation is not available.
Standby (S0 Low Power Idle) Network Connected
Connectivity in standby is disabled by policy.
Apparently I'd set that to "enabled" last year when trying to deal with the wifi flakiness after wakeup. However setting it to disabled now, I am not getting the flakiness so far, so maybe a software update fixed that problem. (Again, fingers crossed).