Thanks for the advice. I knitted my gague/tension square last night and I was 2 stitches (I think) not enough in the required width. My understanding is that if knitted at this tension with those needles (7mm - what the pattern suggests) then my coat will turn out bigger than the pattern. As I already need to make the pattern bigger, will it work if I just stay with the 7mm needles and knit to the pattern, rather than having to use a different size needle to get the correct tension and then adjust the pattern?
Does that make sense? I was also a couple of rows too short with the tension in the length (and I always thought I was a loose knitter!) but I think it's more important to get the width right as I can just add on the extra rows for correct length.