I have been contemplating this migration scenarios:
- do a cold clone to a USB hard drive, then migrate/configure that raw disk image using Converter 5.5 to a vSphere 5.5
- move roles(Schema Master, Domain Naming Master, Infrastructure Master, Relative ID (RID) Master, Primary Domain Controller (PDC) Emulator) to a new or existing DC. After AD replicated correctly, migrate using Converter in DSRM mode. Then move roles again.
I think option 2 will be the safest and supported way. This is a small company with only 1 domain, 1 server.
HTH
Oliver