Wow, so many kind replies, thank you! Imbued with all your confidence, I made a start... Well, I have the quilt sandwiched (I wasn't expecting it to be such a struggle - I suspect something that gets easier with time, shouldn't have tried on a bigger quilt first, I guess!), and I have a single wavy line stitched roughly across the middle of the quilt: the stitching looks fine - but the colour of the thread looks all wrong now!! I spent so long trying to find a neutral pinky colour that would blend in with the fabrics I used, but that line seems to jump out: I am going to leave it overnight before I make any decisions...
Hope your fmq goes well, jonese!