Can I make a functioning bootable Mojave installer on a partition of a thumb drive?

None of the instructions I see online for creating a bootable Mojave installer on a thumb drive mention partitions. Because it would only take 15-20 GB of storage of a 64 or 128 GB thumb drive I plan to buy, I am wondering if I can create a functioning bootable Mojave installer on a partition of a thumb drive and then make use of the remaining space on the drive for files. Your answers will affect how large a thumb drive I buy.