Anyway, I called the gwesty, and after initially lapsing Into English, managed to say when I wanted to stay "yr unfed ar hugain o Ionawr, am un nos" and diolch i'r drefn, the owner understood - "nos Sadwrn?" meddai hi

Unfortunately at that moment I got cut off and had to ring her back. And I don't quite know where it came from, but I was saying, "sori, fi oedd ar y ffôn munud yn ôl - wnaeth rwydwaith fy ffôn symudol ddiflannu!" (well, I'm fairly sure that's what came out) and then I sort of panicked a bit and had to switch to English. But she was very nice about it, and said that she has admiration for learners because Welsh is so difficult to learn. I have to admit I was tempted to say, "But it's not!" But I thought I wouldn't argue with someone who sounded so nice and who let me practise my Welsh on her! And I'm sure she'll hear about SSiW sooner or later…