The maximum amount of casino casino free spins that you can redeem is determined by the casino. You should always read the terms and conditions before you redeem your casino casino free spins, as some casinos have a maximum amount of casino casino free spins that you can redeem, while others don't.
If there is no maximum redemption limit on your welcome package (or in general), then there really isn't much to worry about when it comes to using up all of your welcome offer credits at once!