Cannot find room for the EFI system partition.

MBR2GPT fails with error – Cannot find room for the EFI system partition.

Have you tried running MBT2EFI while in Windows? Normally, the System EFI partition will be placed after the OS partition. If the utility cannot shrink the C partition, it may not be able to add that partition. You do only have 58 GB free in C so I can
see why it might have problems.

It also has to add an MSR partition which is probably 16 MB so there may not be enough room in the 101 MB partition, but just guessing.