I can’t say for sure when it comes to bud, but, I have done this for various other potted plants and they love being watered with ice. I don’t believe it would lower the temp that much for a full size plant. start out with a few cubes and see how they respond, interesting idea… I might have to give that a try
Not sure if this will help much, I grow in outdoor greenhouse in south NV, so Yes we get real hot up to 120f. This summer has been brutal but my girls are fine. I run a drip system and two timers. The auto feed drip runs 4 times a day, 15 min each. But before this happens, I run a simple sprinkler for flower garden and lawn for 25 min prior, same feed as drip system hose. this ensures water is cool. Ice would not last much here, nor help much. Also every 4 hours, I have a simple fan with mister system, not pointed at plants but below bucket line so plants don’t burn, so basically it is spraying the floor which cools it down on whole inside about 15 degrees +. When mister is off fan still runs circulating air.
Hope this helps