The cloud archiving is quite expensive (IMHO), but it is available. You could consider perhaps putting it on one of the replacement cameras (as opposed to both to save money).
https://documentation.meraki.com/MV/Storing_Video/MV_Cloud_Archive
Another option is to put one of the cameras up high out of reach.
If your insurance doesn't cover theft then I don't see the point of it. Claim it on the insurnance. That is what it is for. With any luck you'll be able to get the newer MV22 models. The newer MV22's have more advanced motion search as well, plus you would also gain the motion recap feature.
https://documentation.meraki.com/MV/Viewing_Video/Motion_Search_and_Motion_Recap
I think I would enable motion alerts on the stolen cameras that cover the entire frame. That way if the thief plugs them in you'll get an email and a picture of what the camera is seeing. You should also be able to get the IP address it connected from, which the Police should be able to use to narrow down to a specific address via the ISP.
https://documentation.meraki.com/MV/Advanced_Configuration/Motion_Alerts