Worth it to make a yeast starter from yeast cake 12 hrs before brewing?

I'm about to attempt my first time doing all grain with a pretty standard american pale ale, and also have a pretty standard IPA that is ready to be bottled (from primary, no secondary). I wanted to try reusing the yeast for the first time also, so I was thinking about transferring to bottling bucket tonight to bottle, and then do the washing process for the yeast cake (it's a WLP001 yeast), where I end up with a slurry that is somewhat trub-free... and then make a starter tonight, and shoot for starting the brew tomorrow mid-day.

My question, then, is should I even bother with a yeast starter being this close to brewing, or will the existing yeast be fine as it is after semi-washing it? Or, is it just better to use the yeast unwashed? I did dry hop with an ounce of Palisades, which isn't a hop I'll be using in this pale ale (will be using mostly cascades)... so not sure if that's a big consideration or not.

Also, is it a big deal if you go from a slightly higher gravity beer to a lower one when reusing yeast? The difference won't be too crazy, but it will definitely be downward, and I always read you're supposed to go upward.

Worst case scenario, should I just use a packet of Danstar Nottingham that I have in the fridge?

If your racking off the yeast cake plan on pitching relatively soon thereafter , no need to make a starter. I would rinse w/ sterilized/sanitized water, decant to a couple of mason jars & pitch the appropriate ml as per Mr Malty. Now, in regards to pitching down, it's generally not recommended, however many many homebrewers do it with no catastrophic results. Probably depends more on the fermentation conditions of the yeast than strictly gravity.

Agree with logdrum and bigfloyd. Wash yeast or use straight portion of slurry, either should be fine without doing a starter. Even though it will be a longer day, I would recommend bottling and brewing/pitching same day. For me all the extra time you spend cleaning makes it more efficient to do both the same day.

Thanks for all the advice. i ended up not making any starter as suggested, and just went with the washing process Friday night. I boiled my mason jars, and used some of the boiled water once cooled as my washing solution. I ended up harvesting probably 3/4 of the yeast... I'm not sure how many mL that ended up being that I pitched, but it was quite a bit, so I'm confident I overpitched by a good amount. So, as expected, fermentation had taken off very quickly by the next morning.

I guess I will just see what happens at this point and how everything tastes in the end. I may even use the yeast again, either for another pale ale or IPA?

My biggest problem (I think) with my first attempt at all grain was that I didn't properly account for loss from hot break/trub... so I ended up about .75 gallon short, though my OG was pretty close, I'm guessing because my efficiency wasn't very good? I thought about adding some water at the end, but wanted to just roll with it, and see what the final product tastes and looks like as a result, and learn from it.