I've got 24GB of VRAM, which helps a lot. I'm using the Q4_K_M version of this model, with the KV cache quantized to Q8, and that's able to get me to 128000 tokens of context. I'm using the Qwen Code harness in VS Code.

If 128000 tokens still isn't enough, break the task down into smaller chunks and help the harness out with MCP tools - I installed Codebase Memory to help it navigate large codebases more efficiently, for example. Ask the coding agent what's causing problems and it may be able to help identify solutions too, I've had it troubleshoot itself several times now and it's been quite good at inspecting its own settings and finding where the problems are with them. I even installed Firecrawl for it so it can do its own web searches.