Systems and methods for adapting garbage collection (GC) operations in a memory device to a host write activity are described. A host write progress can be represented by an actual host write count relative to a target host write count. The host write activity may be estimated in a unit time such as per day, or accumulated over a specified time period. A memory controller can adjust an amount of memory space to be freed by a GC operation according to the host write progress. The memory controller can also dynamically reallocate a portion of the memory cells between a single level cell (SLC) cache and a multi-level cell (MLC) storage according to the host write progress.