If it were up to you, would you do Dawnguard without yet having talked to Jarl Balgruff? I'm just the right level, according to Dawnguard ( L10 ). But since I haven't advanced the main story, dragons won't be showing up but I won't be able to shout. So, Durneviir will be the first dragon I have to fight and without shouts and him with Dragon Combat Overhaul.

I would try it just to see what happened.

~But you see what is in my sig...

Yes.

It's the only way I play through Dawnguard, actually. I never do both Dawnguard and the main quest in the same playthrough.

You bet! I've only done Skyrim's main quest once, well before Dawnguard came out. But I've done Dawnguard several times.

I believe the only difference is that for Dawnguard, any locations with dragons simply won't have dragons.

you will have no dragons in skyrim except that durnehviir fellow.

Which is actually very badass. Right?

I've always liked Durnehviir. Tragic dragon. Unique too.

I've even gotten a mod that allows me to ride him using Bend Will.