Invite or No?

Hey all! I know that what I'm about to tell you is a personal choice and in the end the decision is ultimately mine. I guess this is more of a rant than anything because of that, but those in a similar situation- I would love to hear what you have to say! Also it's very long, I'm sorry.


My wedding is about 8 months out (planning to send STDs around 6?) and my guest list is finalized.. Except for one person. My dad.
For context, my father is a drug addict who was somewhat in and out of my life through childhood. My mother raised me and my brother as a single parent growing up, and my dad was allowed to come see us sometimes. My father was never mean or abusive, he was simply a was simply an addict. He wasn't around often but the memories I have of him being around are mostly pleasant and good. Skip to now, my father and I have as healthy of a relationship as we can. I'm not angry and I harbor no ill will to him. He is still 100% an addict with no plans to change and I don't expect him to.
The struggle is that I know he can dry out, for about a week at a time, which he usually does at his parents (my grandparents.) The contingency to his invite would be that a week before my wedding he would need to go up and stay with his parents in order to get clean. He would need to come down with them and be clean and dressed appropriately.
My fiance is supportive and ultimately says it's my decision but I know he's in the corner of "not invite" because he knows that while I am ultimately alright with either situation, if I expect him to go and he doesn't show up at the last minute (very common) but it will deeply upset me and it will do so on my wedding day. He also thinks even if it's a week in advance it would still hurt me and there are clearly a lot of other risks..
The good thing about the contingency is that it requires a week before my wedding, which means that I would know whether or not he was going a week ahead and would not be disappointed day-of. However this does require extra work from me and from my grandparents as he would need a ride to their home out of town. The other issue is that he does have a significant other, but she is not welcome at my grandparents home and therefore cannot go there to dry out and would not be invited (which is against etiquette, or I let her go regardless and that's just stress on a whole other level so.. 😵😖)
Another issue (there are so many I'm sorry) is that he is (obviously) not well liked by most of my family, including my officiant (my aunt) to the point that I worry she may refuse to go if he is invited... I would seat him with his other daughter (my half sister) and parents so he would be with people who enjoy seeing him and could (in a way) keep an eye on him.
If he goes it would be as a guest and nothing more. Part of me worries that may hurt his feelings (I am walking and dancing with my mother) but most of me knows he understands and would just be grateful to be there. I also don't want to negatively impact others by inviting him (I worry his presence may put a damper on the day for my mom or grandmother or etc.) And I get the feeling I may be stressed out worrying about him and his behavior (again, not malicious but rowdy and friendly.) I also don't want the table he'd be with (daughter and her family plus parents) to feel like they're stuck babysitting him.
I think what makes this really hard is that for the first time ever in my life/our relationship, he has been steadily keeping contact with me for about 2 years. He randomly calls me just to say hi and I love you (before this I dreaded answering because it was usually to ask for money.) I just feel stuck.. There are SO many cons, writing it out like this made me really see that and it has me feeling like ultimately I won't be inviting him... However, he is my dad and for all his faults I do love him. You also only get married once (hopefully lol) and I don't want regrets, if I don't invite him I can't get a do over. I'm afraid I may regret it.. I wish I could feel concretely one way or another. I secretly wish I could invite him and he'd disappoint me so I wouldn't have to feel guilty.. And that's real cruddy of me.. 😔
Thanks for reading it all. Any advice from those in a similar situation appreciated.