On the tyres issue, I was staunchly against anything wider than 38s when starting down the gravel road (pun intended) but have found that my new minimum on the front is 45 and in most situations except the smoothest of hardback is 2.4 is my go to. 2.4s are very bike dependant though but I would encourage looking at the wider options. 2x has an advantage if you are on regular paved roads on your way too and from the dirty stuff. It gives options at higher average speeds too. GRX is pretty bullet proof IMHO. If you want to go crazy on the steep stuff, just pop an XT or XTR rear mech on then you can run up to a 52 if you set it up right. I have 48-30 on the front and 11-52 on the back. very much a go anywhere combo with the ability to cruise at 40 on the flats (with a little tail wind). Good luck.