"but I absolutely DON'T want to reduce our offer on the one we want, as its a wreck and we haven't even gone to survey yet, so we might need some wiggle room there for essential repairs etc"
"So, discussion with DH, and we decided that all we could do is try and Do The Right Thing. So, I went to see MrsA to tell her that even if we ended up changing agent, our offer still stands, we aren't about to attempt to reduce it"
But you are about to reduce it, as you know it's a wreck and needs work done, and hope the survey can be leverage for that.
If you haven't prepared the seller for that, she might be annoyed herself now you've said that.
(As your sale progresses, you may want to start a new one about solicitors
)