Heat maps from tables with many rows

GraphPad Prism introduced heat maps. But there is a problem when heat maps are created from huge tables. What happens if there are more values in the tables than pixels in the graph?

Prism 8

 Prism 8 will create a heat map even with large tables. But in this case, some values will be ignored. Prism will make the heat map from every other row, or every third row, or every tenth row... depending on the size of the data table and graph.

Prism 7

Te heat map simply won't be drawn. The limits are:

Minimal height in inches = number of rows / 600
Minimal width in inches = number of columns / 600

In many cases, you can fix the problem by making the heat map larger. But if your table has many thousands of rows, there is no way to create a heat map from your data table with Prism 7. But there is a simple work around. Analyze your data table with the  Prune Rows analysis, which will make a smaller table from your data by averaging every K rows (where you specify K).