I use dry ice for my party every year and it usually lasts throughout the night until next morning, but it's a block rather than pellets. I do the same as above, I line my cooler with towels and wrap it up.
I took a 5 year break myself, but a lot of that had to do with moving from Texas to Florida and not having the space to really do anything. I found that the time away really got my creative juices flowing once I started back. Do what you need to keep you sane and not burn you out!