[Spoilers main] what would be Stannis plan of action if...

If he won blackwater and the tyrells and lannisters didn't come to an agreement.

What would he do next?

Stannis current position - Cersei and her kids hostage, Sansa Hostage, 20000 stormlanders as well as maybe 5000 men max from the crown lands

Enemies - Tyrells still looking for revenge after Renlys death, North and Riverlands a separate kingdom, iron islands independent, Lannisters still against the throne.

Neutrals - Dorne and Vale

What the fuck would he even do from this situation?

He'd have to negotiate with the Tyrells, maybe he can offer Shireen to marry loras, legitimize Edric and have him marry Margaery because if they go against him it's not looking good.

He can wait out the war between the westerman and north/rivermen and negotiate with the Victor but idk what he can really do there.

He can probably crush the iron islanders but even that would take a lot of effort.

In a way it was better Stannis didn't become king because he'd be fucked