Bear in mind it's not an either-or. Go out and let the camera stabilize to temperature, shoot one exposure with the lens cap on (that's your "dark frame").
Then shoot as many shots at that same exposure time as you like, in sequence, no gaps between.
In post processing subtract the dark frame from each of the exposures as you stack. This is the same* as what having LENR on would do, expect no gaps.
*Note: OK, it's not quite the same as temperature changes on the camera from either electrical heating or just ambient air temp changes can make different exposures slightly different. You might try shooting one more dark frame at the end of your series and comparing the two to see how different, and apply the second one to half and the first to the first half if they are very different. Still no gaps.