Thanks for your contribution. I read the last version of the manuscript with great pleasure. This is an outstanding piece of work and clearly lot of time and effort has gone into this.

I only have a few final comments which I’d like you to have a look at (see below). The paper will then be published subject to editorial review
Hilmar Gudmundsson
Comments:

Figure 2. The blue lines are the outlines at LGM, not the outline.
Page 13, Line 4: I wonder if it might have been possible to approximate z_{ela} as a sloping plane similar to done by Aðalgeirsdóttir et al 2003 (A regression model for the mass-balance distribution of the Vatnajökull ice cap, Iceland). Might this might have been one way of creating a north-south gradient?

Page 15 , line 11: The classical result on mass-balance elevation feedback is Weertman 1961 (Stability of Ice-Age Ice Sheets) and you might possibly want to cite that work as well. (Personally I would be very surprised if you were to run into this instability over such an uneven terrain…)

p. 18 l. 5: Keep ice moving -> facilitate ice movement (suggestion)

Dear Authors

Thank you for the final modifications to your manuscript.

Your work has now been accepted for publication in its current form.

greetings
Hilmar Gudmundsson