Exchange Online with no SBS2011 integration

I'm 66 and trying to retire.  We are in the process of moving the software I developed to third party cloud based system.

I would like to migrate our Exchange 2010 to Exchange Online with no dependency on SBS2011 because the plan is to turn the server off on my way out.

Everything article I have found relates to integration.

So, can I use Exchange Online from SBS2011 clients while SBS2011 is still running and continue to use it after SBS is gone.

Thanks