"Low humidity can be a good thing. Many strains grown in high altitude, low humidity climates develope heavier trichome production.
I actually live in a high elevation desert climate... the issue isn't humidity, it's heat. I grow from seed to harvest in 0%-10% humidity with no ill effect. Transpiration and vapor pressure deficit is definitely elevated but as long as the root zone remains well watered, there's absolutely no ill effects.
Here are a few samples of my buds grown in 0% percent humidity:
I'm beginning to feel like it's a blessing to live in such an arid climate. Low humidity does amazing things to cannabis flowers."