JosieGc, I'm glad that you can see the distress of the grandparents because these things are rarely cut and dried. It is also easy to post out of emotion as a new person and then to face a blitz of disapproving comments from regular posters who know exactly how this forum works.
Cleverfairy13, you have little say as a grandparent over access so I'm afraid you will have to make arrangements that take into account the father's access. One way round this might be to invite the father for the time he has access but it doesn't sound like your relationship is good enough for that and he might find that intimidating. If the father is as you say he is then I suspect that things may change in the future regarding the access arrangements. Fathers who show no interest whilst married don't always turn out to be reliable fathers when the marriage ends but often use the child to make a point with the mother. (Mothers can also be equally awful!) My advice, for what it's worth, is to take what you can get with your access and if things change in the future, be there to add support which your grandaughter will need.
I would also encourage your daughter not to make your visit a sticking point in her mediation discussions. She could offer to increase his time for a day or two before/after your visit in return for the same from him but at the end of the day, not making a fuss will avoid more heartache in the long run. Your holiday is just a small detail in the scheme of things they have to work out.
As for your grandaughter disliking access visits to her father, this is probably unfamiliar to her and this may well settle down in time. It is really important that the child does not feel torn between her parents. She has a right to love both parents and providing the father isn't abusive to her then she should be encouraged to welcome his attention. If your SIL is abusive language wise to the mother, get your daughter to ask somebody else to do the handover until things settle down.
If I were you, I would ask Admin to move this post to a more suitable place as for those truly estranged, it might be quite triggering. I would also ask them to remove one of the threads so everything is in the same space. Good luck.