Hey Pirate Girl-
I am not too far from you in geography, so I probably have similar problems.... I put my Sans outside in teh summer where they thrive, and then try to find space for them during the long cold winter. In any case, I have had my Bantel's Sensation about 3 years now. It has been a little more temperamental than some of my other Sans, but it is growing and hanging on. I have had better luck with this one when kept warm and bright over winter...it seems more cold sensitive than some of the others, probably because of its variegation. In the beginning I kept all my Sans in a very free-draining mixture, but with time and experience I have been changing, particularly with the trifasciatas, to soil mixture wiht more organic in it. If kept warm, they seem to thrive with the extra moisture and nutrients. If would allow any new cut rhizome time to heal, but besides that, I think it would be ok to start watering right away, keeping it in a warm location to allow it to actively grow new roots. I don't think Bantel's Sensation would come true from leaf cuttings...you would end up with regular S. trifasciata.
Sorry for your friend and enjoy the plant and his memory!

Pirate girl:
From Norma Cal.

It will need the same condtions as any of your other S. trifascata. "Bantel's Sensation' I have never started from a leaf, no need to. I use a growth from the mother plant directly that already has roots, my plant is 30 years old, I divided it only once and gave half to the Huntington Gardens. I would wait until Spring when the weather in your home doesn't drop any lower than 55F I would give it a fresh lean mix of only 20% organic material, Oak Leaf, or Orchid Bark, or Redwood Bark, no more. The balance pumice and coarse san. We plant all of our San. and succulents, cactus in the same soil mix, and water once a week thoroughly then fertilize lightly. More is not better. With the humidity that the eastern states get I would be stingy with the watering. Growing from leaf which I understand that is what you said you wanted to do is a different matter. I don't know if they will revert back. Plant the leaves in a pot with only 2" of soil, do not bury them, but in as many as you can to a pot, and wait a week befoe you water, again, very sparingly, or they will rot, I don't know if you will get 'Bantel's Sensation' however. A rreminder, plant the cut bottom cut side down. Goodluck Pirate Girl. Norma

Bantel's Sensation is best grown ina media free of acid organic media such as peat. A gritty more volcanic media such as cinders, pumice and sand are the preferred media choice.
An acid media will induce rusts on your plant. Also excessive water available in the soil will cause rust on the leaves. Keep a good air circulation in bright light for best results.