I am pretty sure you would have searched and went through the following discussion, but just referring it again here:
IMO: These can be considered as a 3rd party contract service provider. Most of the 3rd party warehouses are getting certified these days against some form of standard (to satisfy their customer needs), in your case it would be preferred, as well. However, if this is not the case with the warehouse you are dealing with, they should satisfy your company's contract provider standards. Conduct an audit of the site (particularly of Pest control, Food defense, Product release/control- as your product should be low risk due to the temper evident packaging) , unless temperature control comes into play/product based.
IMO: this can be considered a cross-dock if it is stored there for a shorter or no time at all, but in your case it seems like you might be storing it there for some more time, so i would recommend to consider it as a 3rd party storage site.
Hope it helps.