Unless you really dislike moving rooms or you are staying by yourself, just put the 2nd 2 nights stay under the other person's name. You can book Chase Travel hotel stay under anyone's name. I book rooms on Chase Travel for my wife all the time when she is traveling with her friends. You are not going to get the IHG nights for the 2nd 2 nights, but you get extra $100 property credit. After the first 2 nights, you just have to check out and have the other person check back in.