Since this thread comes up easily in Google results, I'll add some more detailed information to Aleron's response. As of at least 2022, Kobo has support for a sideloaded mode (
https://blog.the-ebook-reader.com/20...deloaded-mode/).
This mode can be enabled by connecting the Kobo to a computer or other device, opening it in a file manager, and editing the file at ".kobo/Kobo eReader.conf" (this should already exist) to set SideloadedMode=true under the [ApplicationPreferences] heading. After connecting to a WiFi network the account login step should be skipped automatically.