First starter question...

I have a batch of sourdough starter going and it has been cool here (30s outside and 68ish in the house).  I started it a few days ago and it has been pokey so I put it in my oven at 82-84 degrees.  It rose maybe a cm and then fell.  It smells like sourdough and nothing off, but it doesn't get terribly bubbly or rise a lot... Could my yeast not like to be warm?  It does get a bit of a rise but never double.  I have been doing the 1:1:1 feed daily.. am I feeding it too much?

This is my first attempt at a sourdough starter.