I think you have done well so far. Your daughter must do this on her own--that includes reaching her bottom. She will reach it faster with your cutting strings to her by letting her fend for herself. I know it is hard on your part, but what other choice do you have unless you choose to enable her behavior at home?
Fortunately for my husband and me, our son made his way to his bottom while living thousands of miles away. We were totally oblivious to what he was doing. I appreciate the fact we were thousands of miles away, as if we had known we probably would have prevented him from reaching his bottom when he did. We would have tried to drag him back home with us and started enabling him. As it is it took him four years to progress to heroin addiction which is when he got court ordered to rehab. Who knows how long it would have taken him to reach his bottom had my husband and I interfered with the process.
Regarding your current relationship with your daughter, I remember when my son was a teenager and abusing drugs. I had him in a drug abuse program and the counselor encouraged my husband and me to keep up our relationship with him apart from his drug abuse. Others will make suggestions to you, but I remember the counselor telling my husband and me to not totally divorce ourselves from our son--to have some activity we do with him apart from the drugs. My son likes to play golf as did my husband so they would golf together. My son likes to bowl, so he and I would go bowling.
I think the problem will be if while visiting with your daughter you will stand firm to not enable her if you see her destroying her life. With our son, he was so far away and he didn't share his drug abusing life with us (apart from asking for money). Though we were oblivious at the time, I do see we still enabled him--but not near as much as we could have.