Refrigeration temps

I slow ferment my Ciabatta & Baguette doughs at 37 degrees in our home fridge 36 hrs/24 hrs. My dough is not as lively as it should be. My question is should i set my temp to 40 or 42 degrees where the yeasties are a little happier ? The ciabatta is a rye starter & the baguette is 1/2 tsp of instant yeast in 4.5 lbs of dough.

I'm wondering if I'll get a more open crumb with a higher temp setting ?

Charlie