Move to 40 long or not?

So, I recently had to put my Beardie to sleep and I know I won't get another one anytime soon. I have my enigma in a 20 long and thought it might be kind of nice for him to have the extra space in the 40 Gal. However, I also know that big cages can mess geckos up. What say you? Leave him be or give him more space? I have spare heat pads so I can heat up the larger tank in various places.

Has your enigma had any problems? Just asking because if he has had problems in the past and is now doing good then I wouldn't move him. If no problems then I see no problem moving him to the bigger tank. I would just provide extra hides and make sure he doesn't have any problems finding his food. Post a pic of the new Terrarium when completed!