Came here to mention this gem.Silver Marches (softcover sourcebook)
I added and combined the Neverwinter Campaign Setting to my Lost Mines of Phandelver campaign (plus with the Essentials Kit) to create an even more in-depth Neverwinter Wood / Triboar Trail adventuring area. Adding places like the Dread Ring, Sharandar, and a more complete Helm's Hold etc. gave my players an even larger sandbox they could march through during COVID.The Neverwinter Campaign Setting is absolutely amazing, filled with plot hooks and leads but leaving the DM with tons of options for fleshing out. It assumes the heroes and thus the opponents are heroic levels (1-10, 4e scale), which makes it possible for the party to defeat the bad guys and to actually make a difference. I can't recommend this book enough.
(Combine it with the free Living Forgotten Realms scenarios still available online and you got plenty of adventures to choose from, in addition to adventures from Dungeon Magazine taking place in Neverwinter and of course the Phandalin region adventures already mentioned upthread.)

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.