I have (2) different types of Avocado trees ( Mexicola & Haas )....One was given to me, the other I purchased at a nursery..

Will there be serious damage to these trees if I transplant them into bigger pots with the 5:1:1 potting mix this time of year? I live in Texas... One of the trees is in a sandy soil mixture right now and I can see that when I water this one, it takes to long to drain. The other plant that I purchased was from a nursery and he is in a good draining mixture right now.

I'm trying to see if it would benefit both these plants to be placed with larger pots and a better draining mix. Just worried if they will recover from the shock of the transplant and/or should I just leave them alone for now and wait till Spring time.