What's the best for remote access web cams?

Hello to the forum.

New guy here and I hope I am asking this question in the correct part of the forum.
I need advice on what web cam would be the best for keeping a watch on the outside of my summer home during the winter months. I'll be up front here, I do not know much about computers so simple is best. My needs are to have motion detection and if possible to not need a PC running because of power failures that last longer than the battery back up.(no way of restarting the PC)
I have comcast cable service so a router could be left running for access. I believe the router will restart on its own in case of a power outage. Also I need some way of controlling the temperature in the home by remote or at least be notified if the temperature in the home was to drop below a certain point.
Thank you for any help in this matter.