The sizes you list are only going from a 32” to a 33”. The upsize tire will have a slight effect but I doubt you'll even notice. You'll have no problem with your 7k tt. Even with 35s you’ll be fine. You’re not even towing half of what your stock truck is rated for. When you go 37's+ you want to consider regearing as the change is significant.
I have 35's on my truck and the only difference is a slight drop in mpg. Less than 1mpg difference which I blame more on the aggressive AT tread. I did have the speedo corrected and lifted the front (2" level) so they don't rub. Biggest issue is visual. Looks great without the tt but it sits slightly ass low with the tt hooked up since it doesn't have the factory rake anymore. Could add a spacer in the rear or add bags but it doesn't bother me for the few times a year I tow.