EC1118 is a champagne yeast, you will get similar results to that of the Montrachet strain.
as I mentioned earlier, Montrachet yeast is a well fermenting strain - if you were to back sweeten with juice in an attempt to cut the ABV you would have to arrest fermentation to avoid bottle bombs. to do this, add juice to reduce the abv from 11% to about 7%-8% in your bottling bucket, then bottle the cider. wait 10 days+/- check carbonation - if it's where you want it, pasteurize the ciders, if it's not, check the carbonation each day until it is where you want it, then pasteurize the cider.
to figure out how to get to 7% abv -
you have 256oz*11% and Xoz*0%.
(ignore the units (oz & %) those are just in for information)
This turns into ((256oz*11%)+(Xoz*0%))/(256+x) = 7%
(256*11)/(256+x) = 7
2816/(256+x) = 7
2816 = 7*(256+x)
2816/7=256+x
402.3-256=x
x=146.3oz of juice to reduce your ABV to 7% - now if you were to use 128oz (1 gallon) you would be in your range of 7-8%.
I think my math is correct, but it's early and I haven't had a coffee yet.
Here's the sticky on pasteurization, I really can't add anything to it.
https://www.homebrewtalk.com/f32/easy-stove-top-pasteurizing-pics-193295/
All I can do is echo the safety first comments;
1.) DO NOT try to pasteurize in this method if they are over carbonated; this may result in exploding bottles. The process off heat pasteurization will increase the pressure inside the bottle, so if the bottles are already experiencing higher than normal pressure you are asking for explosions.
2.) safety glasses, tongs, appropriate clothing, a good pot-lid - take all possible safety precautions; don't plan for the pasteurization process, plan for the exploding bottles - even if they don't happen, at least you got to dress up like Mr. Wizard.
hope that was helpful to the both of you.