For both your mini tour and the big trip, I would recommend setting lower mileages the first few days, it helps get the legs into the whole "riding a heavy bike" thing, a bit more enjoyable Ive found. Also, getting out in the morning at a good time to give yourselves more hours to cover a given distance (to a set State Park for example) is a big help in not having to push it just that little too much for too long-again, for both the fun factor and the physical.
In the end, after not too many days you two will find the rythmn and distances that work well for you, thats the important thing, ride your own ride that works for you.
cheers
We've booked accommodation in advance for the mini-tour since camping choices aren't quite as extensive, but it works out quite well as the first couple of days are around 60 miles (depending on detours), with the third day being the longest. I've bargained for 65-70 miles per day, not including rest days, for the Pacific Coast tour; Plan A is Astoria or Tillamook to San Francisco, around 800 miles, 11/12 days of cycling with 2 rest days in between. One extra day to play with in case we need it. How does that sound?