iMessage while without data

Hi,

A real life example where iMessage fails on me, maybe there is a solution for this?

My in-laws both have iPhones so do my wife and I. We use iMessage to message them and it works like a charm as all of us have a continuous data connection, either wifi or 3G.

Now they are on holiday and the issue is now that they have disabled data roaming, but use wifi when available eg in hotel or at public places.

When I sent them a message, it still is sent as imessage(blue bubble) and it doesn't fall back to normal text message instead, even though they have no data.

So this means:

I can not sent them a message, unless I check for myself if the message is delivered and then resent as a text message or they will ony receive the message when they have a data connection again.....

I would assume that when the iPhone has no data, the apple servers would know the connection is gone and automatically and so normal text messages will be used. This is not the case.

I know there is an option sent as text in the settings, but this is for my own fall back in case I have no data and so SMS will be used.

Any ideas?!

Regards,

Ron