Perhaps i'm worrying unecessarily

Staff laptops on old domain with offline file synch on their home drive

Local profiles only offline synch set in group policy

Need now to join laptops to the new domain old domain still available

My plan

Backup home drive to external hard disk

log on as local admin - turn off file synch in folder options

Remove from domain into workgroup

Connect to physical network

Join to new domain

Move required files to new folder

Should this be ok?

Have I missed anything?