im sorry if im missing something at the moment but i have a migraine kicking in and my concentration is somewhere south of the equator....
anyway as i understand the problem, you want to pen test your network while not being connected to it, in other words you want to test it over the internet first?(hitting firewall/dmz first?) if so i would say the simplest solution, without having to look at major reconfiguration and possibly forgetting a security setting etc that the easy route would be to note the IP of your home network, go to any free wifi hotspot with a laptop and commence your attack. If your wanting to look at logs and such as the attack is happening then all you need is to install any sort of remote control software on your home PC's, they can then make the direct connection to routers/logs etc. you could also that way still update and patch holes you find while sipping a latte at starbucks.
Obviously the other route is what others have already talked about, this just requires a little less time invested to get where you want to be(as far as i can tell).
