Graphics card power signal woes

[mjb1]

My Windows 10 PC has on board Intel HD 530 graphics, with displayport, DVI and vga outputs. I use two screens attached to it - one connected via DP, running 2560x1440, the second on DVI at 2048x1152. I'm happy with everything except the bloody power save/control. It's set for screensaver after 10 mins and to turn off the display after 1hr. This used to work fine (except for the occasional incidence when it simply forgot to kick in the screensaver or the power save, so I'd come back to it hours later and the screens would still be lit up as I left them. Obviously that was a Windows bug rather than display adaptor.

Last week I finally succumbed to letting windows 10 update (I've had updates disabled for over 2 years, so it was running a very old edition of W10). Now when the 1hr inactivity comes round, the screens do seems to get the power saving signal from the PC, but more often than not, they seem to partially wake up again after a while. At least one of them then goes through a repeating cycle of turning on, finding no signal and then turning itself off again, approx every 30 seconds. The second display seems to behave a bit better, but even that one sometimes wakes up by itself. I've updated the Intel HD drivers to the latest ones and fiddled with all the settings I can find. A search on google seems to return loads of issues with Intel HD graphics and power issues like this, with no real solutions. If I turn off the screens manually, then when I turn them back on Windows readjusts the desktop to solely the first screen that wakes (resizing and rearranging all my Windows), before picking up the second screen and reusing it, but leaving all my windows in a mess. I don't think I'm asking a lot in this day and age, for a fairly straight forward dual display setup to work as it should?

Assuming that it is the Intel HD graphics and not a Windows bug (I'm sure lots of other people would be complaining about it if it was), then the only thing I can think of is replacing the on board Intel graphics with a cheap PCIE display adaptor. I don't do gaming, just want my desktop spread across the dual displays, I'm I'm not looking for a high powered graphics card, just a basic one with passive cooling. But buggered if I can find anything that has DisplayPort and DVI outputs. I could use the DVID output to drive the higher res screen, but the lower res screen only has DVI and vga inputs (the latter I'd like to avoid using, even if it is capable of 2048x1152).

I believe the PC/windows might be capable of running a multiple monitor setup over multiple adaptors these days - the onboard Intel one and a PCIE card? That might be a solution, although I fear adding extra complication like that may only introduce more issues, or not solve this one properly.