Interesting. They must know something I don't. Myself and everyone I know who has has tried down here has had very limited to no success (even with the supposed heat-tolerant 'Tequila'). I suppose if you "ice" it down every night it's possible. I didn't factor that in because of the tedium involved.
This has always perplexed me as there are Heliamphora growing in the warmer lowland Gran Sabana.