Hello Titan and welcome to Basenotes!
I loved Halston 101 but I have never really found anything too similar to it. The only thing that has come close for me has been Czech & Speake's Cuba. Looking at the notes, one wouldn't make the connection and it could certainly be my nose/ mind playing tricks on me but I have to say that the last time I wore it, I got some strong remembrance of 101.
Could it be the red bottle?? Well, it's a lighter red than 101.
The top notes of Cuba have some mint which I don't remember 101 having but after that I think there is some similarity and I can't really tell you why.
Cuba is $100 a bottle which is steep and IMO it must be sampled extensively before purchase. Too bad they are gouging for the remaining stock and I also have to wonder how fresh it remains. It would be awful to spend $300 and not get a decent bottle of it.
Good luck in your search.