I have walked four times just on insulin via a pen.
I have walked twice on tablets + pen.
I have now walked twice on a pump.
Everyone of us has a different Metabolism.
I think you are looking for an answer that we may not be able to provide. Even if someone was on your regime and had written down the number of every tablet they had taken and how much insulin they had injected, it might be of no use to you. Indeed, it could be dangerous because your needs might be very different. If you followed their plan you could find you're blood sugar levels running far too high or too low.
The standard advice is reduce your insulin by 50% and if that is making you hypo then cut it to 40% and so on. In 1998 and 2004 I was taking an average of 30 units of fast acting insulin for breakfast and had to reduce it to 5 units. I halved my long lasting insulin. I still hypo'd. Frequently. I just drank pure coke and then ate some biscuits.
My sugar levels bounced dreadfully but for the length of the Camino that was a price worth paying to do it.
When I got home I was back to being stable after a couple of weeks and regained the weight I'd lost on the walk though it took several months.
You are going to have find out by trial and error. I appreciate you are not used to doing lots of blood tests, but if you want to go on the Camino that is what you will have to do. Make sure you carry plenty of strips.
I think you only have a problem if you do not recognise the hypo warning signs. If they are clear, don't ignore them. Drink a couple of mouthfuls of coke (or any high sugar drink), eat a couple of biscuits and carry on. If the hypo doesn't clear then you need more coke+carb.
Marylin is right. Start walking locally. Do blood tests before, during and after your walk. Record the results and talk to your specialist on how to interpret them. Do blood tests the day after because the effects of exercise can be with you for up to 24 hours later. As you go build up the weight in your backpack.
If you have a companion as long as they know what to do if you have a bad hypo then you are going to be ok. Your specialist can be reached for advice via a mobile phone, a luxury I didn't have till 2009, so I think you will have to take a deep breath, recognise that the Camino will be taking you out of your well regulated control, and just go for it.
I will add that I have never been able to gain good control of my diabetes, even doing everything by the book. I have never lived in the comfort zone of good control and not having to do many blood tests. Going on the Camino makes me anxious, but it is not terrifying.
If I am right you are very well controlled, with a stable weight and a good regime. If you are fearful that the Camino is going to take you out of that zone, then you are right. To a stable diabetic the Camino provides a huge challenge and potential problems. Overcoming them and realising that you can alter your lifestyle for a few short weeks is deeply satisfying.
For all of us who are diabetics the issue is clear. Do I want to undertake the Camino badly enough that I will live with the bouncing sugar levels, the inconvience of hypos, the extra daily blood tests, the loss of weight and all the other things that are not part of your daily life?
We can only decide for ourselves.
There is only way you can find the answers to your concerns and that is to go. Make sure you have good travel insurance that covers your diabetes and go for it.
