Re: Thoughts on this
I agree. Do not back down on sex. Do not reject her. That has zero chance of making things better. Keep having sex at the scheduled time. The goal is to have sex some other time as well.
Initiate. Not with words. Take her hand and lead her upstairs. If she asks why, say "you'll see". Do not ask for sex. Do not tell her you are having sex. Keep saying "just follow me". If she refuses, tell her "OK, you just lost out on your chance to have sex now, time for me to watch baseball".
If she keeps rejecting you, then you start to reject her. NOT about sex. About other things she wants from you. Dinner time? Make yourself dinner. Or go out by yourself. She wants to talk about her day? Sorry, another game is about to start. "I'll catch you later". When she complains that you are neglecting her, remind her about all the times you asked her to join you upstairs. Make it clear that if she intends to NEVER join you upstairs except the one scheduled time each week, your will feel less inclined to spend time with her doing the things she enjoys. If you get only one hour a week of her time, then how can she expect to get more than one hour of your time?
Of course, if you embark on this path, you might destroy not only your sex life but your entire marriage. So decide whether a better sex life is worth setting a time bomb to your marriage. Many would say yes, it is.
When you can see it coming, duck!