When it was still made (12 per roll) I used to aim to get it through the camera in one day, but I never rushed it to a lab, I'll bet it used to sit around for days (probably the next weekend) before being posted off. I never refrigerated film back then. I've always thought HIE was more sensitive than EIR - I used to load it in subdued light, not total darkness like HIE.

I prefer a yellow filter, sepia is interesting too.

Have you thought about waiting until spring to shoot? There's not much alive this time of year and at 23 per roll you want to get the best out of it.