Ideas for a Cream Stout Winter Warmer?

Cinnamon, ginger, allspice and nutmeg. This is basically "pumpkin pie" spice; but when people think "holiday spice" its often the spice mix that they're thinking of.

As for grains, when you're doing a spiced-beer, I suggest keeping it slightly simple. Roasted barley, some chocolate malt, a touch of dark crystal and a Maris Otter base.

 

For the morning after, I'd make an oatmeal stout with vanilla, cinnamon, and a heavy dose of special B in the grainbill. Keep the coffee in a separate vessel, or do espresso bombs.

 

I was about to say Sam Smith's simple with some lactose.

OP: Just up the ABV a bit and you've got gold. You can add the winter spice after primary is done if you still think it needs something.

One concern I have for you is that you've only got 5 months to let this puppy cool down. If you're thinking heavy hitter, you're just about too late for Christmas or New Year's.

Edit: If it were me, I'd be looking to make an amber or a brown beer with the spices. This is allowed to be boozy. The next day morning stout is a good idea too, but I think you're going to run into trouble making a spiced cream stout. Note: I've never tried.