Certainly 60-65C while gaming would be excellent (in fact, stellar/outstanding) temps for an 8700K....especially if at all-core turbo of 4.7 GHz typical of MCE operation!
Intel's Extreme Tuning Utility has a built in CPU stress test that generally induces about as much stress as Blender/Cinebench and, quite close to that of Prime 95 V26.6/blended, all of which are usually a few degrees above what I see in any gaming load (BF1 is fairly CPU-intensive); so if you are curious as to how well the cooler does under a 'known load', try the IXTU's built in cpu stress test... (I had read the Hyper212 EVO was inadequate for a 9700K, but, if it works for your 8700K, great!)
You can monitor HWMonitor to see what actual core clock speeds are...