Also: treat your opener like your last warm-up. This maxim gets thrown around a lot, but rarely is it taken to heart.
If you have a goal for this meet--to, say, set a PR--then you should treat your opener like the last warm-up you'd use before attempting that PR. If you want to deadlift 210 for your second attempt, I would put your opener in the 180-185 range, as others have suggested. If you haven't missed it ever, then that's all the more reason to use it.
At the end of the day, your opener should be a springboard towards a good, heavy second attempt, and a second attempt should lead to an all-out, gut-check third attempt. But keep some perspective: you and I are both relatively small lifters, and in the grand scheme of things, are numbers aren't that high. The difference for us between 85% and 95% is a matter of a few pounds. For you, twenty pounds separates a 95% lift from an 85% lift. That's so inconsequential that there's nothing to lose in taking away another five or ten pounds to make an opener even easier. It's not like we're 1300-lb. squatters who would be dropping 100 lbs. off an opener to drop from 95% to 85%.
So, stay in the 180-185 lb. range. If your meet goes as planned, your openers won't count as your best lifts anyway, so why even worry about how much they are?