I've frozen plenty. I do it the super scientific way. Wash yeast, pour into mason jar, place in freezer. I make a starter using about 2x the amount I should to account for loss. The dead yeast should be a nice nutrient. I use a mason jars worth of wort from my previous brew as a starter. That too is frozen then thawed.
I haven't had any complaints with this process, but can't give you hard numbers or the science.