Well, I haven’t done this. Though I believe you have only three options.
A longer ethernet cable so you may move the home base 3 in a central position of your home closer to your cameras.
Relocate the cams closer to home base.
Wi-Fi repeater/extender to connect to your homes Wi-Fi with LAN/ethernet port to connect home base 3 via ethernet cable. This would give you some choices for the placement of the HomeBase3 depending on where you have electrical outlets.