in the bike trips I have done over the last decades, it has been rare that I have had to leave my bike locked up somewhere other than at the campsite Ive been at, either in N America, or France or wherever. Given that this is your honeymoon trip, you'll probably visit more museums etc with your wife, but in the end, most places with people around and not at night, leaving two bikes locked together with two locks is going to be ok. Ive always brought coil locks, but I guess if you will feel better, one U lock and a coil lock will pretty much be fine for the usual "lock the bikes outside" at places for a visit.

bottom line is that there are no guarentees in life about stuff like this, but I still figure using common sense and a good spidey sense for where or where not to leave bikes safely is the main issue here.