The only problem is that you need to remember to turn off a Culture Victory - otherwise you are likely to accidentally win via that condition first!
It can be done without turning off other victory conditions. The key? Only make a small set of great works, and move those as necessary to use Eleanor's effect. I just finished a "soft" domination victory with her, but I had to use very strict conditions (took me several tries):
Marathon speed, small map, 3 opponents, Pangaea, no victory conditions turned off. I specified Canada, England (Victoria, of course), and Australia, because they don't seem to have good defenses against loyalty. I actually won on turn 990 or so, but took the last city on turn 996.
Key strategies: build cities as fast as possible, grow cities as fast as possible, and get those Theater Square and Entertainment districts. You have to get to Golden Age and stay there the whole game; I spent one era in normal age and it worked out because Canada (my first target) ended up with a dark age, so I still had the advantage. My trifecta of mayors was Magnus (for settlers), Amani (for enemy loyalty penalty), and Reyna (for buying districts). I found playing defensively with respect to religion, military, and science was important. Australia and England attacked me a couple times, and their focus on science and military made things dicey for a bit, but by the time I had absorbed Canada, I had a good science and industry base to maintain defenses against other victory conditions. The World Congress proposal that increases growth but reduces loyalty by 5 was also clutch; I burned a lot of diplomatic points making sure that was used on my intended target. I even managed to absorb one city state even though I wasn't trying. Developing a couple experienced spies is clutch as well; knocking off mayors and reducing loyalty won about half of the cities I took. To avoid the cultural victory, just don't use your great people to make great works, except for the small amount you need to fill your theater square buildings (I found two sets--4 writing, 6 art, 2 music) was enough since the most theater squares I could get near the enemy cities before I was moving forward yet again was two.
I have a screenshot of the last few cities in England I took; Hull fell last after I had already won the domination victory. Australia was in the north central region, I started in roughly the east central area, and Canada was in the southeast corner. I fought no offensive wars, and had to defend myself against Australia and England twice.
I give her free stuff all the time when she's in trouble even when I need it. A good husband should take good care of his dumbass AI wife who attacks Maori despite being much lower in troops.
