Well Baja covered most everything but something I wanted to add about your soil mix. I would in the future advise against not using sand in mixes, it's partial size is actually very small and can actually reduce pore spaces in soil mixtures while having a stronger soil water retention capacity. Your best bet would be to remove to sand percentages and up your rates or perlite or other larger stone aggregate.
I have done field capacity tests and soil water retention capacity tests with sand in soil mixtures and it actually can prevent the fast draining you are aiming for. Especially depending on where and how you put the sand in the mixture. And it also leads to lower oxygen levels in the soil by clogging natural pore spaces.
While yes it may have a higher pore space ratio than clay particles but much smaller than using larger aggregates. Most sand you can easily get is a very fine particle and actually stays wet for a long time.
I have actually used sand in seed germination mixes that I want to hold onto water a little bit tighter, but not because I want to mixture to drain better. For that I'll use larger particle size stone aggregates.
Just my two cents in on how you can get a faster draining soil especially during the dormant winter months.
