I told them I would bring them extra flashlights, batteries and water but they should get themselves perishables.  

We use solar energy and batteries to power any electrical equipment.

I also have an abundance of detectors of both types, and I hardwired them so no lapses from forgetting to change batteries.

You CAN spend even more money and get battery backup with this mode... so if the power goes out you can have a small amount of energy to run things other than the HVAC or stove... like a medical device.

Emergency Contacts and Guidelines If something needs to be repaired or replaced:Please contact xxxx, LLC by sending a text message to xxxx at 303-xxx-xxxx.If you do not receive a timely response, please also try 303-xxx-xxxx.Fire, medical, or police emergency:If it is an emergency call 911.Please replace batteries in smoke and carbon monoxide detectors as needed and leave them and the fire extinguisher(s) in place.

Are there notable benefits to going with the wired option, besides not having to recharge the internal battery every X number of weeks or months?

It has a long list of criminal history, from misdemeanor (battery, domestic, theft), to felony (stolen vehicle, drug...). 

Lithium battery EV is a dead technology.

Fuel with 4amp/hr battery will last longer than the sears impact driver itself.

If you start doing things like this, you’ll be receiving calls for a plugged toilet, replacing batteries at 3 am in a smoke alarm, a noisy neighbor, etc.