It has been previously discussed that the network thinning will complement either other. The best of both networks will remain. More Sprint sites than T-Mobile will be decommissioned or moved, but where Sprint is stronger (or the only one present) it will remain.
More than what I've got here. 10x10 band 2 that's deployed as 5x5. Non-contiguous 10x10 band 66 that's deployed as 5x5. 5x5 band 12. 20x20 band 71 that's deployed as 5x5. Gives me a grand total of 20x20 for LTE.