Got a Christmas gift of a 3 -pack, and it comes with 3 months "free" of the Smart service, but I'm a cheapskate an don't want to pay for a service. Can I record to my router? (I haven't even opened the package as I decide whether or not to keep them.)

Depending on which model it is, some (older models) have a 7-day free recording option, but it will be to the cloud (depending on the base station you may have the option to record locally to a hard drive or SD card plugged into the base station as well).

[kb.arlo.com]

But chances are, if you don't want to pay for a subscription, you should exchange them for something else.

I went without a subscription for a long time. I relented as it comes with the ability to set zones. Other than that decision the cameras have been rock solid. Nary a glitch.