My heat tape is too long
Usually you can wrap the tape around the pipe as you install it. You can then add or subtract wraps to adjust the length and make it come out where you want. This works well for just a short amount of slack.

OR

For longer amounts of slack, most heat tape has a bump on the outside of the cable every 18" or so. You can cut the heat tape and install a plug or terminator just after the bump to shorten the tape. Refer to your heat tape's instructions before doing this.

Good luck!