I am running pd -nogui on a Rapberry Pi. I copy new patches and start new processes via ssh, but it's getting somewhat tedious. I'm wondering if there is some way to connect the Purr Data GUI from my laptop to the pd instance on my Raspberry?

The easiest way to copy/paste the patches is to set up a network share for the Pi for your home network. In fact you can open the patch on your computer through the share, and save it back to the RPI without copying it..........
I am using mostly Windows computers at home so I use Samba. I am no Linux expert.... but these are my notes from when I set it up on a RPI....... (not a complete tutorial)

sudo nano /etc/samba/smb.conf  (windows file sharing)
  for passwords add users:
sudo smbpasswd -a root (if you wish)
sudo smbpasswd -a pi
    and then check with:  pdbedit -L (needs sudo?)
sudo /etc/init.d/samba restart (re-start samba)

If you are running Mac's on the network the Linux Samba share can be made to work for them as well....... https://www.howtoforge.com/community/threads/mac-osx-client-and-linux-samba-share.77380/

After you have saved your patch on the RPI you need control of Pd on the RPI to be able to open it.
I have attached the files below....... and I hope [netsend] is the same for Purr Data.
You will have to have the rpi_receiver.pd patch open already.
Maybe start Pd on the Pi with a script at boot that always opens [rpi_receiver]

Here are more messages you can send to Pd on the RPI........ http://puredata.info/community/pdwiki/PdInternalMessages
Don't send [menuclose( directly to Pd as that will quit Pd.

The same could be done to send messages to tk/tcl (the Wish app) via [hcs/sys_gui]...... and to the Shell via [ggee/shell]

You can use another [netreceive] within your patch to control it from Purr Data once it is open.

NOW******** it gets more complicated because you are going to want to close the patch before opening the new copy..... and as menuclose will quit Pd you will lose control.
But rpi_receiver.pd can do it ....... and menuclose can be made safe like this......
remote_command_safe.zip
David.

What you are suggesting however, will definitely improve on my workflow, so thanks a lot!!

I am able to get it to somewhat work with a command like:

pd -guicmd "ssh -R 5400:localhost:5400 laptop pd-gui 5400"

It's kinda clunky, and I'm still not sure if there is a Purr Data equivalent to the pd-gui command.