Let me step forward and try to answer this.
IMO there is no OOTB procedure of migrating Infopath application without issues.
One should hack and use workarounds in order to migrate Infopath form (workflow) app to another site/machine).
While there are advices to use Data Connection Files ,UDCX, I do not see how they applicable to Onfopath form templates of tyoe/compatibility Sharepoint List Form and/or Workflow Form which Main Data Connection is non-editable (unavailable for modifications and creation of data connection files from/to it) and locked.
And, you should probably ask it in Microsoft forums to get them know about the common and obvious requirements.
This is really a FAQ question
The same question with a more attendance on this site