I think if you're getting 5 good minutes, as you said in your original post, you're doing great. You can accomplish a lot with 5 minutes a day, adding a minute or less every few sessions.
We started in 30 second increments at our groomer's recommendation, and did that for a couple of weeks leading up to her first appointment, and we tap or rub her nails every day while we're relaxing in front of the TV, inspect her ears, rub our hands or a brush over her, etc., always keeping it short and positive.
Pushing past their threshold does you no favours in the long run. You'll likely make faster progress moving extremely slowly, because you'll avoid setbacks.
How old is Noodle? Peggy was groomed only once before she came to us at almost 9 weeks, and is now groomed every 4 weeks, with each appointment building on the previous appointment's progress. We kept her puppy fluff until 6.5 months, with only face, feet, and sanitary area shaved until that point.
We've never pushed her because it's important to us and her groomer that she be comfortable with this process that will be such a big part of her life.