Query re: upstreams and two protocols

Hi all,

First time posting here so apologies for any faux pas etc…

I have an nginx config where I have a server block, a location block and
proxypass in the location block, pointing to an upstream.

The upstream has, at this point 3 servers in it.

All the 3 servers are in the same vpn. The proxy_pass directive pointing
traffic to that upstream uses the http protocol

I want to add another server into the upstream endpoints, located in a
remote datacentre. I want traffic to this remote datacentre to be
over https.

The proxy_pass can’t handle http and https simultaneously

Any ideas how I can have an upstream containing the 3 servers in the
datacentre that shouldn’t use https, and the 1 server in the remote
datacentre that does need the traffic to be encrypted with https,

Someone suggested putting a server definition in the upstream that
to a local nginx server definition that’s designed to just forward off
another upstream with an https proxy_pass command, with the second
holding the remote datacentre server definition but it seems a bit

Thanks for any advice!