If you had more time, you could make as large a starter as you wanted... Cutting it this close, though, you could have some issues. Unless you're going to be pitching the yeast late tomorrow (evening?) I would just make a normal starter and pitch it as you would have. Then just harvest/wash the yeast once the batch is in bottles. You'll have a lot of yeast that way...
If you're concerned about getting the trub out of the mix for washing yeast, use the nylon bags for your hops. I typically use one bag for each timed addition, with no more than 1oz going into each bag.
BTW, I don't have a stir plate yet, so I'm unsure of what impact that will have on the amount of time needed to get the starter to finish. I wouldn't make another starter right away for what remains. I think you'd be better off just storing it in the fridge (let it settle out and store just the yeast, plus some spent wort) until it's time to make the starter for the next batch. That will also let you make a more properly sized starter.
Just my take on this...