Is the driver vib in use? if so you can always download a newer driver (assuming it is supported and compatible) install it over the top and it should also install dependencies. Once done reboot and then upgrade, failing that you could always just remove the vib if you are certain its safe and then upgrade?
An upgrade from esxi 6 to 6.7 is a huge leap and personally the config on an esxi is so minor its quicker to just reinstall and reconfigure.
I'm not sure whether a configuration backup can be restored to another ESXi version/build.
Anyway, depending on the number of hosts you have, it may be worth a try to upgrade the hosts from the command line using the Offline Bundle.
To do this, upload the Offline Bundle to a folder on a datastore, and find out the profile name from the bundle.
esxcli software sources profile list -d /vmfs/volumes/<datastore>/<folder>/VMware_ESXi_6.7.0_13006603_Custom_Cisco_22.214.171.124_Bundle.zip
With the profile name, run the upgrade using
esxcli software profile install -d /vmfs/volumes/<datastore>/<folder>/VMware_ESXi_6.7.0_13006603_Custom_Cisco_126.96.36.199_Bundle.zip -p <profilename> --ok-to-remove --dry-run
Note: "--dry-run" is optional, and can be used to test run the command, without actually changing anything.
We ended up doing a fresh install and all is well after a few tweaks