Time delay estimation in low SNR
Quite often, performing a time-delay estimation in a transformed domain can help,as long as the signal gets better concentrated, and/or the noise is more spread. 

So performing the CC or GCC in a time-frequency or time-scale (wavelet) domain could be useful, as long as you can select the frequency  band or the scale in which the correlation will be meaningful. 

If the noise characterics are unknown, you can benefit from wavelet whitening capabilities.

You can check for instance:


On Wavelet Denoising and its Applications to Time Delay Estimation, 1999


For Matlab codes:


Wavelet Cross-Correlation for Lead-Lag Analysis
modwtxcorr: Wavelet cross-correlation sequence estimates using the maximal overlap discrete wavelet transform (MODWT)