This is the only plain porridge which comes in at 5.5grams per 100g. I searched for months and months for a porridge and this was the closest, some are over 8grams and more. If you want a porridge with flavours, then are some.
There are oats so simple sachets, they are over the 5g though, the single tubs are ok though.
It depends on how firm you are with the rules. Asda do a good oat variety, check them out when you go shopping.