As the guys above mentioned you are looking for a Disconnected Template. It will take a USB thumb drive, format it to be bootable on BIOS or UEFI machines, copy all the necessary provisioning bits, the agent (if using a self contained EXE agent), the image itself and the unattend.xml file. When it runs it can perform all of those actions without any access to the core. Additionally, actions such as execute file, copy file, make directory, etc. that don't require any network access will work. For many other actions, such as map drive, if you have access to the network, but not the core it will still work. If you try to do something that requires communication to the core, such as software distribution, HII or patch, then it will only work if we can talk to the core. In short, we'll for sure get you to a place where you have the OS deployed and an agent installed. Anything after that will depend on your ability to communicate with the network and/or core as needed. It you have that communication everything will work fine.
There is also one 'gotcha' we are aware of. In order to boot on UEFI devices we have to boot off a FAT32 partition. Right now we are formatting the entire drive to FAT32. Unfortunately that means there is a 4 GB limit on individual files. Since most images are larger than that you would need to use split the image up. On ImageW that has to be done at capture time. On ImageX you capture the full image then run a DISM command to split it. In the future we'd like to make a small boot partition followed by a large NTFS partition, similar to how a normal hard drive would be formatted. Until then, the workaround is to split the images you capture so no individual file is larger than 4 GB.