I also say go for it. When our kids were younger we toured alot with tandems, only graduating to there own bikes at I believe 14 or o. But if yours are comfortable/capable of cycling on their own bike why not. It sounds like you are being reasonable cautious for you first trip picking something off road (though I would hazard that even someplace with very light traffic would be a good start). I think the biggest thing is to make sure its fun for your children - lots of stops at interesting places, which includes water where kids love to throw rocks. Have fun.