Last year at this time I was in the same position. Once it got too cold to use the pool, I left it open for about 3 more weeks but stopped adding anything with Baq in it. When I closed the pool I did use the closing kit sold at the pool store for non-chlorine pools. When I opened the pool this past spring the water was in decent shape, just a little cloudy. I immediately began the conversion using about 50 gal of chlorine to do it. Overall it took about 10 days but only the first three were intense with lots of scrubbing, vacuuming, flter cleaning, etc. After that it was just maintaining the chlorine level until the FC went to zero. My pool has never had cleaner, clearer water and it was soooo easy to maintain this summer and so inexpensive compared to Baq.
Good luck with your conversion. You will not regret it.