can you bring not in the mixed dry ingredients (your suggestion of Tupperware) and use the office milk (contributing to a kitty perhaps) ? That removes a large element of the messiness. However tupperware can be quite bulky and isn't easy to pour out of sometimes. For handling those dry ingredients without mess I recommend baby food containers something like this:

small, convenient, tight caps.

this would also mean you don't need to keep the mix cold as its only dry.

I advise against creamers as they just aren't that nice (I tried it). Pre-added milk does seem to get absorbed in the flavours and I think you'd possibly be disappointed.

Since its only dry ingredients, you can just wipe them clean.

Can you bring not in the mixed dry ingredients (your suggestion of Tupperware) and use the office milk (contributing to a kitty perhaps) ? That removes a large element of the messiness. However Tupperware can be quite bulky and isn't easy to pour out of sometimes. For handling those dry ingredients without mess I recommend baby food containers something like this:

small, convenient, tight caps.

This would also mean you don't need to keep the mix cold as its only dry.

I advise against creamers as they just aren't that nice (I tried it). Pre-added milk does seem to get absorbed in the flavours and I think you'd possibly be disappointed.

Since its only dry ingredients, you can just wipe them clean.