Big beer, yeast starter, and stepping it up

Saturday I intend to make my biggest beer ever, a Big Irish Red with a goal OG of 1.110 or so. I brewed an irish red that I harvested the yeast from, that OG was 1.071. To do a starter for my 3 gallon 1.110 OG brew on Saturday, is it easiest just to make my 900mL starter on the stir plate (I only have a 1L flask) at 1.070 because the yeast already fermented out from that OG, or should I start lower and add higher gravity wort to step it up tomorrow? Calculating the amount of yeast I need, I should need a little over 1L of a starter, but I don't have the ability to do that unfortunately.

I a bit confused, when you say you harvested the yeast from a red, did you wash it? If you didn't, there should be more than enough yeast to just dump in and get some good fermentation going fast. If you did wash it and it's been in the fridge for a bit, I would make a starter and step it up once before pitching. Since it doesn't seem like you have time for that, do the biggest starter you can and pitch it at high kreusen. Also, make sure you aerate the wort really well since you're going to need some serious cell division.

Yeah, i was a little vague there. I washed the yeast and they have been sitting in the fridge for 7 days. I plan on aerating as much as possible and it'll be much easier with 3 gal vs. 5.5gal.

I think the biggest starter you can on the stirplate pitched at high kreusen is good advice, but I'd stick with the standard 1.030-1.040 SG starter and not 1.070 as it could stress the yeast.