Typical losses with LNG are about 0.1-0.15% per day depending on the type of carrier. A round trip around the cape would add probably 20-25 days or so for a typical ship. More for slower ones. So, the price of that is 2-3% losses. The value of LNG fluctuates wildly in recent years. But it's not cheap. At the peak, a single ship could be carrying hundreds of millions $ worth of LNG. So, a few percent losses is quite significant.
As the gas heats, it will expand, boil off and be vented out. Meaning every additional day is more lost product.
This could be helpful for other ships though.