From what I have experienced and read, the rate of infusion is probably the major factor for tolerance not as much the dose in a day. Since we have nerves that may have IV IgG bound to them (as opposed to people that get IV IgG because they do not make enough themselves), people with GBS/CIDP may be more sensitive to receiving it. I only got IV IgG a few times, but found that I could not tolerate a rate of infusion of more than 125 to 150 ml/hr or I felt like an donkey was sitting on my chest. This means that it took a long time for the infusion (60 g of 6% is 1000 ml given over about 8-10 hours with the ramp up). People with neurological reasons to need the IV IgG are not the same as people with other reasons to need it.
One needs to be careful if you have kidney issues or hypertension or have diabetes with the dose of IV IgG. It is a protein load on the body–so can annoy the kidneys and some forms of IV IgG are stabilized with a sugar or dissolved in a solution with some sugars.
Some people say that the manufacturer of IV IgG makes a difference to them with their condition. The home infusion company that you tried may have used a different product or rates of infusion. The manufacturing processes differ in the purification steps, stabilization, amount of IgA (which some people are sensitive to having present), etc. If one has a way that works and then tries to do it at home, they should make sure that it is done the same way at home (rate and hydration status, etc) and that they get the same manufacturer. It might not make a difference with them, but if they do not feel the same after the home infusion, it might be because of these differences.
WithHope for a cure of these diseases