if you can get the entire rootball and soil out of the container smoothly and easily.. which you should be able to do, I would transplant...don't try anything tricky... just pull the plant in one smooth motion and position it in a prepared 3-5 gallon pot... water thoroughly...

iloveyou

you always are at risk of shock.. but it is unlikley when th plant is mature and has a good solid rootball..

iloveyou