Restore From Time Machine Backup With Incomplete Backup as the Last one I am using macOS Mojave 10.14.6.  I had performed a complete backup on 6th Dec.  My machine was then formatted and the OS re-installed.  Subsequently, a backup took place before I could restore my files.  It also stopped midway. It is
2020-12-09-073227.inProgress
But the latest backup as indicated by the Latest folder is also taken on Dec. 6th. Will the Migration Assistant ignore 2020-12-09-073227.inProgress and restore from the latest backup?
Yes, inProgress backups are ignored by Migration Assistant in my experience. Migration Assistant usually lets you choose which backup you would like to restore. In progress backups don't show in Time Machine when browsing the backup history until they are completed, so they also don't show in the list of backups to restore in Migration Assistant.