Pretty much anywhere I park when I'm at home I can see my home wifi.
Are there any cams that can connect to it and send push notifications to my phone when it detects impact while in parking mode?
on your phone yes, but that's not to say a dashcam will be able to do the same.
And there is also the other way around, can your router see your dashcam in the car, cuz they do have weaker wifi than other wifi devises.