Nothing is foolproof but some things don't take a brain surgeon to defend against either.
Hardwired, even if only one or two cameras, overrides the wifi jam.
Having offsite video recordings gets a pretty picture of the guy as he goes to cut the building power. Oops, too late, already on candid camera.
For discussion purposes we need to separate the nerd in his basement 1,000 miles away trying to show his prowess by taking over your cameras from the would be thief wearing a ski mask as he cuts the battery backed up power to your house. Well, at least the router and enough of the surveillance cameras are still on, or have already done their work.
Lastly, I don't live in a gated mansion. I won't be attracting the kind of thieves they make movies about.
At this point I will just buy the new AX router and depend on my complex passwords to defend my humble abode. If I want to revisit the VPN issue, there will probably be a DD-WRT flash available within the next year for the new router. If not, oh well, I tried.
Thanks for your input R. Proffitt.