Which component upgrades for longer rides I have a Giant Escape 1 (2016) which I use for commuting to work and back. It is fitted with Altus level kit.

I was considering taking my bike on holiday with me to get in some longer rides, perhaps some parts of the Trans Pennine Trail. Nothing too excessive, perhaps 50 to 60 miles a day, which I know is nothing to many riders, but to me it's a step up from my 8 mile commute. The trail is mostly off-road, dirt track, but nothing too rough.

Would it be worth my while in the long run considering upgrading my components to say Deore level? And if so, in which order for "most bang for my buck"? My current setup has Tektro brakes, so I'm thinking that might be a good place to start?

Any thoughts most welcome
If your goal is comfort over speed, I would emphasize in three upgrades which don't break your bank:


Find a comfortable saddle. Go to your LBS and ask their opinions. A lot of people suggest leather saddles, like Brooks or Selle Anatomica. A good saddle is expensive, but it is a worth upgrade and you will be surprised how big the difference is between a cheap saddle and a good one. If you are on a tight budget, a padded short is a cheaper option.
Do you use a bike rack and panniers? for a long ride especially on hot weather, a set of pannier is better than a backpack.
I think your current tires are already pretty good but it might be worth a try to have wider and fatter tires for more comfortable rides. I assume your current tires are 32mm wide, so upgrade to 35mm tires.