It's up to you, not the doctor. You already were diagnosed with celiac, there really is no need to do another test. There is no need to physically make yourself ill by eating gluten just to prove celiac to the doctor. Even if you did not have celiac and were gluten intolerant, you know gluten makes you ill. There is nothing in this world that would make me eat gluten for any test. I get very sick with just a tiny cross contamination of gluten, less than 5ppm will make me so sick.
It's just my opinion, but I wouldn't allow this test. You already know gluten is a huge problem for you.
It doesn't matter where or when you eat gluten...the effect will be the same, you will get sick. The comfort of your home will only make you feel better that you are sick in your own surroundings, and that isn't much comfort to me, not sure about you.
Maybe you could suggest he do gene testing. Since you already had the blood work done, gene testing could confirm that you have the DQ2 or 8 genes that are considered celiac genes...you do not have to eat gluten for this test, it's just a blood test.
Also, 1 and 1/2 week of eating gluten will not flatten the villi enough for him to find it in testing. They say at least 6 weeks of eating gluten and I will not do that to myself.