I don't use any asus software, use RealTemp to test you loads etc. Anyway on RealTemp, my temps are 47*C-50*C idle. I have our heater on so it might be 23 or 24 in the house.
My CPU is passively cooled so it gets up to 88 or 90 loaded at standard 3.8 OC. I think the Sandy cut out is just above 90 so its OK if u are 90 or below.
This is a SB (an the sensor), yous might be similar.
https://rog.asus.com/forum/showthread.php?4386-Maximus-IV-Gene-Z-motherboard-Temp&p=47378&viewfull=1...Looks like my CPU idle was 28*C when I could be bothered tweaking the bios, lol.
The trick to reducing heat at idle is probably VCCIO, that is what I used to lower to match my low volt ram... but I would not worry too much, just play games.
https://www.google.com.au/search?as_occt=any&as_q=spathi+VccIO+site:rog.asus.com