I am looking to build a bike for long distance cycling trips, as self sustained as possible, through Europe and her mountains and possibly beyond.

I am more familiar with old bike tech than modern tech, have serviced cup and cone wheels / bottom brackets , work on tapered axles, know how to true a wheel etc.

I also know how nice modern bikes can feel with their sealed bearings and efficiency and lightweight

Should I go for something modern and familiarize myself with that tech or don't bother with it. Remember I want do be able to do almost all maintenance in the field and rely on bike shops as little as possible. My thinking is that old bike tech is easier for field repair and build to last longer is that right?
I think it's easier to carry some bearings and a cup of grease but then again modern sealed bearings are less exposed