Well, if you're out with the tent and children going 100km, assuming you're towing a trailer, then you'll have to have a) a dual battery system, b) carry an extra battery, or 3) have charging capability and several hours to recharge at the halfway point. You might be able to do that with a 750W/h battery and the 250W/h range extender for the Smart System. The dual battery equipped System 2 bike will do that for sure.
If most of your riding can be done with the Smart System bike with a range extender, I'd go for that, simply because it's the latest electronic technology for Bosch. You could always carry a second range extender for the trailer. If you just want to power up and go anywhere you want to from the jump, get the System 2 bike.