2 kinds of yeast...

OK I was just sitting around thinking about a few things so forgive me if this is a dumb question. I am a noob, I have my first batch in secondary and my second, third, and Apfelwine in the works.

Can you double pitch a batch with 2 different kinds of dry yeast, say Nottingham and Windsor ale yeast for a high gravity batch like a RIS?

I just thought that the different characters of the yeast would be present but just toned down since they were both in there....

Just thinking about this and want some other people's 2 cents.

And say I want to do this and make a Winter Warmer, could I ferment in my basement at around 58 F or would that yeast go dormant? Maybe since there would be so much yeast sat least some would survive the lower temps?

With something really big like an RIS you would probably want to pitch two packets of dry yeast anyway in order to get enough cells in there. Using one packet each of two different yeasts vs. two packets of the same yeast probably wouldn't change much in terms of their success at fermenting the high gravity wort though.

As you figured, using two different yeast strains to ferment the same beer should probably give a combined flavour profile somewhere in between the two yeasts used on their own.

58F is really stretching it for most ale yeasts, though with the added heat from the fermentation itself your beer would probably be a few degrees above the ambient temperature. So as long as you kept it somewhere a little warmer while waiting for fermentation to get going you might just squeak by fermenting in the basement.
Having more yeast might start it generating its own heat a little quicker, but I don't think increasing the pitch rate will really do much to enable you to ferment at lower temperatures.

You can buy some mixed strains like Wyeast 9097 Old Ale Blend and Wyeast 9093 Imperial Blend. I think there are more. Sure you could mix them yourself. There is only one way to find out the results. I'm pretty sure Windsor would just go dormant at 58F and Nottingham would end up doing most of the work.

The only reason I thought to double pitch and reduce temp would be to make it have a more lager like flavor, and maybe to reduce esters, since the kit I want to do is an extract kit from NB called Baltic Porter, which uses a lager yeast Saflager S23. I want to age it for around 4-6 months to try that process of making a big beer for the first time.

But basically I asked the question just out of pure curiosity. I am learning so much on this site and appreciate everyone's help.

I used the search function so I am breathing life back into a 3 years old thread... sorry if that is not cool.

I made Ed Wort's Apfelwein but I accidentally added 4lbs of sugar instead of the 2lbs the recipe asks for.
Classic case of too many cooks spoil the soup, my gf and I were doing different things. Anyway, we added
Safbrew WB06 because we heard it would leave a fruity flavor. My question is if we want to use the extra 2lbs of
sugar to increase the alcohol level can we add a yeast like lalvin ec1118 after 3 weeks? Is there any downside
to this in terms of taste? I have a lot more questions but any advice would be greatly appreciated.