Unlock Map Size library (module) is dedicated to remove 8/128MB map size limit in Warcraft 3.
Patches 1.26a-1.28f have been confirmed (all of them are somewhat the same, apart from the 8/128 difference).
Simple place this file in your Warcraft III root folder or in Redist\Miles that also resides in the root folder.
Not as far as I know, this method has been used in my WFE (Warcraft Feature Extender) for years and no issues have been found. The only potential "downside" could be ICCup's AntiCheat that seems to detect map size limit remover as a cheat, but that has not been really confirmed.