You have it already so you might as well set it up now and see if you're happy with the performance of the current pc. If you are then there is no need to upgrade
You're right, didn't mention this but i am going away for 10 days 2mrw and that's been partly the reasoning too.
My wife is currently away visiting family in Stockholm and i am joining her Friday.
She doesn't know ive treated myself to a new monitor either so kind of looking to set it up and hope she doesn't even notice

I remember when i went from my 60hz monitor to a true 144hz monitor and was completely blown away by it, hoping for the same experience