all very good opinions from experienced tourers. Your present 26/32, soon to be 26/34 should be realistically low for loaded touring, as my and others can relate to vis a vis our experiences and bike set ups.

As I stated before, you may want to look at the weight you are carrying--perhaps look up previous thread discussions to see if you are more than other people. Remember, on my first fully loaded tour I had too much stuff and with really hard hills it was murder. I learned the hard way.

Ditto on the training side, if you can train on hills, it makes such a difference for prepping your legs and knees for a trip. Its always hard for anyone at any fitness level to be suddenly schlepping umpteem lbs on a touring bike, especially with hills, so make it easier on yhourself and go out of your way to do hills, it will pay off. Even a daily commute with some hills works great, doesnt have to be big hills either.

ps, ditto for never "cross-chaining", granny-smallest cog, or biggest chainring-biggest rear cog---it just aint good for chain, derailleurs, wear. This should be an instinct for all bikers.
I too avoid using the smallest rear cog nearly all the time (unless on a big downhill in top gear) just because I know it works the chain more etc.