The 3T Exploro is a great bike. I have test ridden the previous version and thought it was really nice, especially once you have two wheelsets for it. So not matter what groupset you get, I think this is a good choice for what you have in mind. And 3T is smart enough to give customers the choice.
Let’s talk numbers first: if you are worried about climbing gears, don’t, both have the same lowest gear (within fractions). The Force AXS 2x has a taller top gear, though, roughly equivalent to 50:11 whereas the EKAR tops out at roughly the equivalent of 50:12. So measured on a compact chain set, you are missing one gear at the top.
However, if you want to do super long distance rides, I am quite certain that this won’t matter, especially if there are no mountains where you live. Even in mountains, you are mostly limited by traffic. So in terms of gear range, I don’t think you will feel this limitation. The EKAR cassette has its tallest jumps at the climbing end of things, which is IMHO sensible. Even on road rides, I rarely use my 50:11, I can spin happily at 50 km/h if wind permits in my 50:13.
A lot of long-distance riders and bike packers go 1x (e. g. Rides of Japan). For example, if memory serves one of the recent winners of the European Transcontinental Race was on a humble 1x11 SRAM Apex1 drive train. I couldn’t find a link, but I think he just had a bog-standard 11-42 cassette in the rear.
One more thing about 3T: they are willing to customize your bike. I’m going to order a Strada very soon that is quite custom, and I will just have to pay the price difference. So if you e. g. want to have SRAM’s gravel crank (43/30), I think they can make that happen. That’ll give you even lower gearing and still plenty at the top end. Or you could ask them to put in Campagnolo’s 10-44 cassette.