What a sweetie! And it looks like the carrier will be "just the thing" for awhile (then you may need a larger one!)
I used to leave my brief case by the front door; Puddie would jump in it when I wasn't looking, trying to sneak out with me in the mornings. It broke my heart to have to take him back out ... but it earned him a little extra lovin' and a sneak snack that the others didn't get before I left
If he's quiet, you may be able to sneak him into stores with you