Is your Organization (Dashboard) using Co-termination? (most Dashboards are)
You can check under Organization > License info.
If so the key thing is that everything is licensed together - so must be renewed together - you'll see in that page a single expiry date for everything.
To extend that date out significantly, you'll need one licensing order that provides coverage for all the meraki devices in that Org that you still want to be working, once that renewal has been applied.