I can tell you 100% that low carb for type 1 works. I also lived in South Wales and know that the nurses telling me to eat porridge or toast for a breakfast were wrong....and double my size as well!!!
I was under Carmarthen CCG. It was the only time in my life that I have gone above a size 10.
I've been a lower carber for best part of 50 years and T1 30+ years.
(I did have exceptionally good care though and no problems getting a pump within 2 weeks due to a hypo incident!).
I never test to see if I'm in ketosis as I have problems keeping weight on....
I have added more fat in to my diet from advice on this forum but this is purely in the form of olives, avocado, oily fish and large qtys of olive oil dressing. I did try adding heavier creams and cheese but I wasn't happy with the cholesterol results.
When I was eating more carbs my insulin usage was more.... Both with basal and bolus.
I was brought up with minimal bread, potatoes etc and never ate pasta but rice occasionaly with a takeaway. I now have slow colonic transit and any bread etc gives me huge problems but as I never used to eat it I'm not bothered. The only thing I think I miss is that I used to have time off and enjoy Xmas pud and Xmas cake but I daren't eat that now as I know it won't process through my stomach...
So yes.. Low carbing is possible. My nurse at my current hospital in England also low carbs and is 100% behind me for eating the food that I do... So it was lovely to get a change in attitude last coupl months when for the first real time ever I was asked how I keep myself slim and healthy!!! She was horrified that diabetes nurse and others could suggest that carbs were necessary!!!
Hope this helps....