I think that you'll find that doing a 2:3 instead of a 1:2 buy/write (months out) won't make much of a difference if there's a large down move but when you compare the higher decay rate of the 1 month put versus the somewhat lower delta of the 3 month call (compared to the 2 month call in the other position) you'll find that with the 2:3 you give up some of the upside and in return you'll have not quite as bad a result if the UL goes nowhere. It's pick your poison priceQuote from jones247:
I'd like to bounce the following adjustment to the calendar collar off you. Instead of buying a front month put (30 days from expiration) and selling a 60 day call, I would move all transactions an additional 30 days out. In other words, buy a 60 day put and sell a 90 day call. The plan would be to make the adjustment (i.e. roll) or close-out the collar within 30 days after establishing the position. The theta impact is most aggressive in the last 30 days. Therefore, I would aim to never have a long position with less than 30 days to expiration.
If I needed to make an adjustment/roll, I believe that I could close-out the call & put after 30 days, then open a new 60 day long put and a new 90 day long call.

EDIT: That reads really poorly (g). The 1:2 does worse if the UL goes nowhere but does much better to the upside. That's your tradeoff.