JamesRL

My 80s touring experience was on a department store frankenbike - looked like they wandered around various parts bins and threw something interesting together. It had a good frame and geometry for touring, and all the right attachment mounts for racks. But it had 27 x 1 inch wheels. I was about the same weight as you. I did get a pinch flat after bunny hopping some railroad tracks (not a good idea with a loaded bike), but I didn't have a single problem with the spokes. I swapped tires for something wider and more flat resistent, and better tubes, and I was fine for that tour and every one afterwards.

I wouldn't be quick to change the wheels, I would ensure that when you get the bike and when you go on tour, that the spokes are properly tensioned. I have never owned a tension meter, always plucked the spokes to see if there was a spoke that was out, it is easier than you think. If the wheels are well set up, you should be fine. I notice the tires are a good size for touring and puncture resistent.

I suggest you try some day trips or weekends loaded up the way you will be on the longer tour. Think of it as a shakedown cruise.