I agree with AS and LH. I don't think your wife is out of the ball park from being WW. But the signs are positive. Don't have your walls too high you miss the signs you need to make important decisions.
If she is taking the time to write you letters. Than she's prioritizing you. She's thinking about you. And what you are doing is working. The OM attraction is wearing off. Her tears aren't a sign of her making a drastic change, but it is a sign of a form of remorse.
Don't overlook these signs and take them lightly. We can only go off what you wrote, when giving you advice, and from my perspective, she's showing signs off realizing the damage she has done and what's she's on the verge of losing.
Something you wrote did concern me. When you told her that you needed to contact the OM in front of you and she became apprehensive, that's still a sign of protection. Either protection of the OM or their relationship. Do not relent on the last contact letter, email or phone call.
Yes, please don't push to make all these changes over the holidays. Waiting until after the holidays is good. Work your boundaries.
Onward and forward
M:37 W:37 T:11 M:10 S17, S13, S10, S4 BD:06/28/17 OM confirmed 07/20/17 Recon the M 10/29/17 Working hard:2gether
Onward and forward
This process is not a sprint it's a marathon! Patience, Patience, Patience.