Home Depot.
I have never seen a CFL instantly on with its max output, ever when its cold. If it was used recently and you turn it back on, you don’t have the issue. But if its been off for a while its a guaranteed 15-30 second wait for them to put out their maximum light.
They do come “on” instantly, but they don’t remotely give their max output instantly when cold.
I haven’t time it yet, but when it is cold outside and the lamps are cold it is many minutes before the light level is worth much. Therefor, in an unheated garage or shed, they are not good in the winter, without a long on time.