Sum values in cells to meet a certain criteria

This seems really complex to me if not impossible, but I'm out of ideas...

Scenario : A client wants bourbon shipped to their warehouse in Chicago, directly from our production facility. From the Chicago warehouse they then send it out in various qty's to several different store locations. We can only fit a maximum qty of bourbon on one skid, that skid will contain product for several different store locations. We must make a sheet to put on the skid that lists what that skid contains (qty by store location).

Since there is maximum qty we can put on one skid, by trial and error we have to add up each each store location qty to meet that maximum number (doesn't have to be exact within a ballpark range). It's a tedious and annoying process and we're trying to streamline the process to make the task easier.

What I'm trying to make is something to make it somewhat automated so that the trial and error is eliminated. I have a spreadsheet made (excel file is attached) that is somewhat close, but it won't take into account other quantity's that could be used to get closer to the maximum qty on a skid.

It may require a ton of IF and SUMIF statements. That's all I know

Any help would be greatly appreciated.