Bought the game at release, finished it in May. Last patch I had installed was 2.2.1.6. Now I'm getting ready to have another go with the game but find I can't update it to the latest version because some intermediate patches I guess I need aren't available anymore. I have a relatively slow internet connection and would like to avoid downloading the full game installer again.

So ... anyway to do it?

While you are "getting ready", or waiting for answers, you could have downloaded the game again. Besides, what is meant by "relatively slow"?

Contact support. I think they have provided patches in the past, so if you explain your situation, they might take pity on you.

Same here. Last patch I installed was 2.02. In my case I just don't have the data allowance this month to download an extra 9GB, and I hate to waste that much data next month on a game I already have. I mean, it was only 6 months ago that I played this game, you'd think they could leave the patches up or at least make the patches able to update from earlier versions.

I also have this problem, only I contacted GOG, and they say they can't/are unwilling to provide patches. I also have a download limit that would be sorely taxed by redownloading PoE. I find this a very perplexing approach to customer service.

This is the response I got from GOG:

"Unfortunately, I can't provide you with the older patches for Pillars of Eternity. If you have version older than 2.03, you will have to download the latest installer from our website, via GOG Downloader or GOG Galaxy.
I apologize for any inconvenience caused."