85psi is good, but 100psi is better! Only my opinion, but lower rolling resistance is always nice on long tours.
You know what they say about opinions though "they are like armpits--everyone has a couple, and most everybody ELSE thinks yours stink!"
That said I also have 26x1 1/2 tires, but on ISO559 wheels. After looking around a fair bit, I found Schwalbe Marathon 100psi max tires that work very well. The difference between 85 and 100psi might not be a lot, but I am willing to take any help I can get! It just makes it a little easier to get back on the bike the next day.
One advantage of lower pressure is riding on dirt or gravel--a little less (say 80% of max) helps tires roll OVER loose surfaces, instead of through them. Just be careful not to overdo it--beware the dreaded 'snake bite'! And be sure to "Pump It Up" once you get back on pavement.
If you REALLY want higher psi tires, you may have to get new wheels. This would also simplify finding replacement tires--at home and on tour, should you ever find it necessary.
As always, you should decide what works best for YOU, in light of (or in spite of) all the advice.