Well, it does not wakeup from S3, as planned before, but from ACPI sleep. (That is probably S4 or S5?). The power consumption is even better (S3 it was 1,8W and now it is 0,7W). So I'm fine with that.
I have tested it several times this afternoon, and it really works even with 10 minutes timeout setup only (= quite short).
I have tested the latest 64bit beta before, without success. Also the other VDR distros (ct vdr, etc) weren't waking up from the sleep out of the box. Maybe the Intel Mount Washington is too new to have right drivers, but with the beta the frontend was without video and either of the sleep modes (S3/acpi/nvram) didn't work out of the box. So I went for the 0.3.2 / 32bit and as I wrote, everything was OK except the wakeup, which now works.
For me, if I will not watch the video often, is the 32 bit version OK. The only disadvantage is quite old version of the "live" web access. (It cannot be configured, how many mins before should the recording start and how many minutes after should it end) May it be upgraded by apt get?