You can use BOS or GUI BOS by Nitesh to open channels from your cold wallet. https://github.com/niteshbalusu11/lndboss

I personally do not like that. I like to use the 3 levels stash: hodl, cache (nodes), LN spending. But I understand you "pain" that you want to avoid that intermediary transfer from cold wallet to node wallet and then open a LN channel.