When last we saw my Warden, she was hitting the mid-40s. I ran most of the quests one conveniently could in all the zones I listed. I never found groups for the Angmar instances, but I did solo the rest of Volume 1.
That puts you at 55, with no skirmishes, instances, or grinding. That is your measure of how much 45-50 content there is in LotRO: it lasts you until 55. The 30 seconds I spent in Moria were to drop off Book 1 of Volume II (unlock legendary items, so I could start earning IXP).
Also on the “with no grinding” note, I finished my legendary trait pages at level 53. You can start finding those pages at level 39, so that is how long it took with no effort devoted to farming. I can only imagine how horrible those pages were in the very beginning when only one type of monster dropped each set of four. That grew to humanoids in two zones (half of each book in each), then humanoids in four zones (half of each book in each pair), and I am told that any humanoid in Moria could drop any page if I still needed them.
If I wanted to, I could skip Moria entirely by running/riding the entire length and starting on Lothlorien reputation. But that would be silly.