Over the years, I've found that stamina tends to be more of a personal issue. I say this because many of the underlying issues for "being able to execute a full set in an acceptable manner" can vary from dancer to dancer, whether physical fitness, motivation or mental discipline. Trying to increase your team's stamina as a whole may require a more of a catered-to-individuals approach rather than a one-size-fits-all undertaking.
I completely agree that doing run-throughs is 100% absolutely necessary. This is your bread and butter - runthroughs are the best. But many dancers find that they hit a plateau in terms of stamina from just doing runthroughs.
If you don't see yourself having more energy in later segments without better execution in earlier segments after doing multitudes of runthroughs, chances are that you're hitting your plateau. For those who workout, I see it similar to increasing your one rep max on bench. You can keep hitting the bench press and you may see some little gains after you've hit your plateau, but you'll be able to blast through that limit if you begin to focus and strengthen your shoulders, triceps, back, core..etc and vary up how you train your chest in weight, frequency & volume. Likewise, if you acknowledge the other components that are critical for you to dance through the routine for the full 8 minutes (while executing with good form, high energy and precise technique), you'll be able to get more out of your run throughs.
Personally, for me, looking back in the past few years, my stamina was highest during my performance at Bhangra Idols 2012 (
https://www.youtube.com/watch?v=IPZWfo1Yiko) (I'm the dashing young fellow in blue with slight beard

). The following are some of the things that just worked for me back then - maybe, others may benefit from them as well.
1. Get fitter. Stay healthy.
It still perplexes me how people sometimes miss the connection between fitness and dancing. You don't have to be super fit to be a good dancer, but it can only help you. Yes, you can get lose fat by doing runthroughs, but working out with weights will see you benefits in good form, better execution, better energy and better aesthetic appeal because of increased muscle strength and better posture. Back in 2012, I worked out in the mornings before work and my day culminated with practices that I basically treated as cardio sessions. The strength you can gain from working out results in fuller extensions, deeper squats and higher jumps. Being healthier makes you a better athlete which makes you a better dancer.
2. Practice with isolated segments (even after full routine is done).
It's not rocket science to realize that once you hit later segments in the routine during a runthrough, your energy levels drop, your precision may become haphazard and sometimes execution suffers and sometimes this softer, weaker execution becomes engrained in muscle memory to the point where you may not consciously realize how far from the original (standardized) execution it truly is. One way I tried to circumvent this was to continue to practice individual segments in addition to doing full runthroughs. The former allowed me to reinforce the way I wanted to execute the choreography and I was reminded of it and was able to recognize shortcomings during the actual full runthrough instead of after while watching the practice video. This also served as good internal motivation for me while dancing through each segment of the routine.
3. Increase your mental strength.
Even if you're conserving energy through a physically draining performance, there comes a point for most dancers where, even though you may be able to finish the set at 100%, your mind has begun to manifest excuses to start giving up in terms of energy and you begin to deter from your quest to finish how you intended. One of the ways I strengthened my mental toughness back then was by taking
Scottish showers. Google it to get a full understanding of what it is and all of the apparent benefits, but in a nutshell, it involves showering with hot water and turning to full frigid cold. In the few seconds it takes for the water to turn to ice, your mind begins to think of excuses for you to give up. But in the end, if you persevere in this daily internal struggle, you realize that your mind was more afraid of the shock of the cold and that the cold itself isn't that bad at all. With working out everyday and with long unrelenting practices, your sore body will also thank you but the mental toughness you develop as a result of forcing yourselves to cold showers will not only invigorate your mornings but it will come in clutch during times of high stress and physical strain. On stage, at Idols, it snapped for me at around 6:46, essentially right when you start nearing the end of the routine, when you normally would feel like giving in and simply just going through the motions, maybe even stop lifting legs as high or even stop completely finishing moves, if you focus on improving your mental toughness, you'll have gained more of a mindset and willpower to bolster through without sacrificing the quality of dancing in these key final moments of a routine.
There's a bunch of other things I tried to increase my personal stamina & quality of dancing that had varying degrees of success but that will be for another time, another BTF post.