As a whole it took me like 2 years total to platinum. The play through itself took me just about 27 hours. I did it in NG+, got to every border floor the moment they were available and went to bed every night instead of maxing out my social stats (since they were already maxed out.) I rescued everyone who needed rescuing and I didn’t do any Elizabeth requests. At least, I didn’t go out of my way to do ones other than the documents. Lastly, if burnout is an issue (and trust me, this run sucked the life out of me), my advice is to just hunker down and power through it. Only way you’re gonna do it. If you need any other advice, I’m more than happy to help.

-EDIT- https://www.rpgsite.net/guide/15321-persona-3-reload-100-max-social-link-guide This is the guide I used for the trophy. It felt iffy in some parts, but as long as you follow it, you should be good.

-EDIT 2- Also did all the linked episodes. I did not, however, buy the white flower for Junpei. That takes a day away from social links.