Lump sum to DCA threshold?

I know the prevailing strategy is DCA and hold. Is there a point to where one makes more sense than another?

For example I want to start putting in $2k USD a month, vs 500 every Friday.

I realize some may consider 500 a lump some and just say DCA 125 weekly instead. This could prob be subdivided a few more times. I would also like to keep UTXO's and transfer to cold storage fees in check.

My use case/strategy for bitcoin is long term preservation of buying power, with a hypothetical sell point down the road when my stash is sufficient enough to pay off 3 mortgages.