NG+ Frenzied Flame Ending plus DLC replay question

So I went through Elden Ring and Shadow of the Erdtree as a mage. After a couple of years I wanted to play both again with a Strength/Faith build. I won the main game with that build, but accidentally moved on to NG+ before replaying the DLC. On top of that I also realized I’m only a Frenzied Flame Ending away from Platinum. Now I really want to get the platinum and replay the DLC.

I’m thinking I’ll get the Frenzied flame ending, say no to ng++, then play Shadow of Erdtree again with this character. Is that doable? Is the DLC too punishing on NG+? Thanks!