You don't need to smack them so many hours before. I typically take mine out of the fridge the morning of the day I am brewing. Once it's been sitting out 2 hours or so I pop the packet inside and start prepping for brewing. By the time it takes to heat water and steep the grains, then bring the kettle to a boil and do an hour boil the pack is fully swollen by pitching time.
You can also expedite the package warming. I've put it between my hands, under my armpit (lol), and even exhaled on it with warm breath to warm it up quicker. Always works well. While brewing I will also often shake the pack here and there, helps it swell quicker.