This could be a huge topic but I'll keep it brief...
My TDEE is typically 3500kcal.
Ive run tren going as low as 1800kcal, but not for sustained periods (maybe 3-4wks at that intake). I've continued to set PRs and look joocy. I haven't done any body composition scans, but anecdotally, subjectively, photos and tape measure would indicate I kept my muscle mass at the very least. Tren was usually around 300-400mg ace. But also always with masteron in the mix.
Very helpful, especially the timeframe you dropped that low. I know I cut down to 2100 and like you said strength and size gains are still noticeable. Thanks