I applied to a funded PhD opportunity a while back at College A. It's in a different field than mine, but the proposal I put forward bridges my background (social work and social policy) and the subject matter at hand (media studies). I went through the interview process and I really struggled to answer their questions, so I presumed that the interview went poorly and that I'd likely not be the successful candidate. I am aware that this being a different background to mine entirely was likely going to be a weak spot on my application, and I did the best I could given the circumstances.

That was all well and good though, because the day of the interview with College A, I got an email saying that I was being invited to interview for another funded PhD opportunity that I'd applied to with College B. They are the institution I did my Masters in, the opportunity is with my Masters supervisor, and if I am being honest while I am deeply motivated to pursue the project with College A, College B is my preference because the subject matter is definitely more aligned with my background and I know what kind of supervision and supports (especially around ADHD) I will receive at College B. Also, if I'm successful, the stipend I receive is slightly higher per year (by 2000 Euro). Additionally, it would be a later start date (in March instead of September), so I'd have more time to get myself ready to move back abroad (these opportunities are in Ireland, I'm currently in Canada) and to look into housing and get things sorted with my cat.

Anyway - I got notified recently, to my great surprise, that I have been offered the funded position at College A, and I have no idea how to process this.

Any advice? I want to accept the offer from College A because I do want to do the project, I think even if it is a departure from my field I will find a way to make it make sense for my career trajectory (interdisciplinary research and connections are necessary in this work), and it's a guaranteed, fully funded offer. However, my interview with College B is on June 18, and I don't find out about whether I will be the successful recipient of the funding until June 28 - more than a month from now.

Do I tell College A that I have an interview already scheduled with College B, and I just want to confirm whether that opportunity is viable first, or would being transparent about this potentially impact their decision? I don't want to take an opportunity away from another potential candidate either. I genuinely did not think the interview went well, so this totally took me by surprise. However, I don't want to miss out on an opportunity with College B if it's more aligned on paper and in practice with what I am looking to do career-wise.

Thanks in advance. I am so stuck. I have never had an opportunity like this before, and I have no way of self funding a PhD, but I've been determined to do this since my undergraduate. I don't want to turn down an opportunity like this because it feels like it's once in a life time. So any advice would be super helpful.