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.