Which do you want first, the bad news or the bad news?
You can't prioritize traffic over the general internet and certainly not from home offices with residential internet.
The whole internet is being stressed right now and I would try to find other solutions besides VPN wherever possible. For example, file sharing through Dropbox or similar and screen share with VNC, etc.
Client VPN is just going to work a little worse than any other type of connection because of the encryption overhead and resources it takes on the firewall and client machine.
- Ex community all-star (⌐⊙_⊙)