If I have a $100,000 long term capital loss, can I use it against next year's capital gains?

You have no choice about how or when capital losses are used. The calculations have to be done as specified in the tax laws. TurboTax will do it automatically.

The long-term capital loss will first be used to offset any capital gains (long-term or short-term) in the same year. If that doesn't use up the entire loss, up to $3,000 of the remaining loss will be used to offset other income in the same year. If the entire loss is still not used up, the remaining loss will be carried over to the next year and will be used to offset capital gains in that year.

If you have further questions, please clarify in what specific year you have the loss, and what year is "next year."