Backup SCCM server or Secondary server with different patch level

[sywitt]

We recently had a situation where a SCCM patch broke our imaging capability.  After weeks, I finally found the solution. 

My boss asked if there was a way to have a secondary server that we didn't patch, for availability in case we have this problem again.  I suspect that in this particular situation, it wouldn't have helped because the issue was in the DB, but it's worth checking for future 'situations'.

Our server is virtual, I'm thinking we can clone the existing instance (including sql) and if we have a problem, we can shut down the existing server and bring up the clone with the old version-or maybe restore from a snapshot.  Will this cause problems with the newer clients? 

What high availability solutions are you folks using?

Thanks in advance.