Roaming Profile for offline users?

Roaming Profile for offline users?

We have offline users who are assigned their own laptops that go onsite.
They are provided aircards that can get internet access and VPN back to
the company server. The laptops are part of the company domain. These
people occasionally comes back to the lab but we don't want them to unpack
their laptops but to just use the workstations that are in the lab
already. What we want is a solution that allows for roaming profile even
for offline users so they have the same profile on both the lab computers
and their laptop. The Windows roaming profile seems like a good candidate
but I'm not sure it will handle the offline situation since it seems to
only sync during the log on/log off and the field users won't be "online"
when that happen so any changes they made on their laptop won't be sync
back to the server.
Are there any solution out there that will handle our situation?
Our environment: Windows 2012 Domain Controller, Exchange Server, Remote
Desktop Server
Thank you, Kirk