Like you, I have an Intex pool.

As a season extender, I built my own wood fired heater. Not all that efficient, but it does work.

One caveat with mine, though, is that I have to keep a very close eye on my pH. If I let it get too far from 7.2 - 7.6, I could easily introduce copper from the pipes into my pool water.

If you have the means to purchase a heater and pay for the fuel for it, yes you can heat your Intex pool.