As long as you keep an exported vault backup safe somewhere such as a usb key (encrypted with personal password option is ideal), and the 2FA recovery code and master password written down in a secure place (ideally separately), you should have no issue loading everything else into Bitwarden.
If you do choice to use a separate Authenticator, don’t forget to export the QR codes for backup and print and store for Google Authenticator. Raivo OTP has an encrypted export (keys and QR codes) and it also backups up to iCloud.
Crap, I just finished changing all my important passwords (came over from LastPass) and thought I was so careful to then put the files in Veracrypt after downloading (new to that). Now I will change them all again and download into the opened Vera Crypt container.
dan
If you are really worried about your plain-text vault being written to the disk, you should also disable swap file and hibernation. However, even after this, there are still a bunch of other local attack vectors that could lead to your vault being exposed to the attacker. In nutshell, you are screwed anyway if your device gets compromised, so I would just recommend following common good practices on securing your device and enjoy life.