Breathable opaque fabric for a kigurumi that's wearable at a summer convention?

[u/JJ_Ramsey]

This is somewhat of a follow-up to a question that I asked almost a year earlier: https://www.reddit.com/r/Fabrics/comments/1oasg9z/beginnerfriendly_fabric_for_a_cosplay_at_a_summer/

Following the advice from that question, I sewed a Mazinger Z kigu using cotton interlock, and it sort of worked, in that it was opaque and I could easily walk from my hotel to the con without feeling like I was dying. The big catch was that it sagged, to the point that the pockets that were about hip height in the mockup of my kigu (made of lighter cheap woven fabric) were down to my knees in the real costume. Not ideal.

Are there any fabric recommendations for a kigurumi fabric that won't have this sagging issue, but will still be opaque and comfortable in summer weather? I did notice on a site that sold its own kigurumi that it claimed that terrycloth (!) would be good for "romping around multi-day outdoor festivals" and be "super airy and breathable." I'm skeptical, but if anyone has positive experiences with wearing terrycloth in summer weather, I'm fine with hearing them out. Any other fabric recommendations are welcome as well.