I switched from maps to gps devices fairly quickly.
When I started to hike, I once got stuck on a ridge in Scotland for 3 days because of dense fog and not being able to use maps to navigate as there was no visible trail or visibility to see landmarks.
Ever since then I relied mostly on GPS devices.
During my six week hike in the Arctic I relied on a system of having a solar charger, a battery pack, a satellite phone and gps device.
This was easy in the Arctic as in spring and summer it is almost always light and the sun never sets.
This allowed me to charge my devices while sleeping.
My plan was that if there was any point of failure, my solar charger or gps device, I would fall back on using the gps functionality on my phone and make my way to safety. However, it would have probably been wise to atleast carry some maps and a compass.
I opted for this as that particular hike in the Arctic stretched 700km, and having detailed maps of that entire stretch would have meant a lot of extra weight and space.
In the Arctic I used the garmin explorer plus (Satellite device + gps). And a solar charger from Goal Zero (I have found these to be very good)
Anyway.. I am pretty sure a lot of more hardcore folks would scold my over reliance on technology.. but it works for me and as long as one point of failure doesn't knock out my ability to navigate it is worth the risk for me.
A good 4 season tent is a must. I have two 4 season tents from Hilleberg. The Akto and Nammatj 2. The Nammatj 2 came to good use hiking off-season (fall and winter) in Scotland. With wind speeds of sometimes over 100 km/h in exposed terrain.
I would also carry a sewing kit with repair rope used for repairing sails (which is pretty strong!). Heavy duty stakes and extra guy line rope if there's a possibility of severe weather.
Having reliable shelter is very important when you're not hiking in Summer, or when hiking in extreme environments.