+1 for what Colm said.
Depending on the quality of the cable (the thickness of the cable is one measure), you may also be able to get 1080p/60 with deep color disabled.
Basically what we are all telling you is that High Speed cables cut off at just over 25'. Since you have a 40' cable, you weren't going to be able to get the high speeds that HDMI uses. However, 1080p/60 is not near the highest speeds, particularly with Deep Color disabled. Cutting that cable and then trying to re-terminate it will likely result in a non-functional cable and could also damage the equipment it is hooked up to. You'll find many topics of people who either 1) were unsuccessful in re-terminating an HDMI cable or 2) have invented this great method for re-terminating an HDMI cable that wouldn't be necessary if re-terminating an HDMI cable was easy.
If you do work in a cable shop in China, can you get us HDMI cables for less than Monoprice charges? How about new iPads? You probably shouldn't admit that, so nevermind - just pretend like you don't work there (wink, wink).