Been awhile, but when my son was not quite 3 years old, we spent a month overseas, living out of hotels. The one thing I did NOT pack (looked at it, decided not to, and kicked myself the entire time for dumb last minute decision) was a little cheap inflatable ball (we had gotten one as part of Toy Meal from one of the restaurants in town and it would've been perfect) - was about maybe 4 inches in diameter, like little miniature beach ball, blow it up, push the stem in, when done, pull stem out and deflate it. As it turned out, we found one at a "Everything's A Dinar" store, like our dollar store, so it worked okay - but my son LOVED playing with it - was toddling over to pick it up and we'd throw it to him, and it was soft enough to not damage anything in the hotel room.
Another thing I DID do and was happy I did, was I packed a small bottle of Lavender essential oil - and would put some on my chest before I nursed my son and a little bit on his chest and nose area so he could smell it - helped him calm down and drift off to sleep. This would work with your infant too as I started this with my son in his infancy and still do it sometimes now that he's almost 10!!
You might need two of the balls just so the infant can have something he can look at, especially if it has a variety of colors - can be showing him the colors, shapes, designs, just things to talk about as well as to have the tactile experience holding something.