Hey Dan... did you ever figure this out? It's been a long time but I believe I ran into the exact same type of issue a few years back... the Metabase settings didn't work the way I had expected... I'd definitely turn off the setting - "Rerun queries for simple explorations"
Also - here's an article about enabling caching on Metabase - if you're data is getting loaded once at 12am then there shouldn't be any reason for queries hitting Snowflake except for adhoc reporting....
I hope that helps take a step in the right direction.