So to paraphrase your post: "I'm super excited to play this game, but I don't know anything about DnD and I need encouragement". Here's your encouragement: go for it!
About Lone wolf playthroughs, as others have mentioned, Larian is likely going to implement options for that later on. But even in EA, you are not without options. You may play as a stealthy rogue, sneaking past encounters or employing guerilla tactics - shoot, kill, hide, flee, repeat. Or you might give warlock a try, conjuring darkness that only you can see through, rendering yourself invisible - a notoriously strong but team-unfriendly strategy.
That said, DnD is a very team-oriented game where every character brings a unique skillset to the table, unlike Divinity, where anyone can do anything and a solo character can be absolutely self-sufficient. It's part of the fun, and makes every character feel very distinct. In Divinity, characters barely cooperate beyond dealing damage to the same target, but in DnD, everyone provides at least something the others can't. If you decide to try BG3, I encourage you to give the full party gameplay a try too. It's also going to be a much more narratively focused game than Divinity, the world is rich in interesting lore, and your relationships with your companions are going to develop dynamically over time. Who knows, perhaps you'll even take a liking to DnD
One last positive bit in case all that teamwork stuff still doesn't appeal to you - in both previous Baldur's Gate games, soloing was a thing. You just had to know what you were doing.
