Hi UG's

I currently play on a DOT ES-335 with .010/.049 Ernie Ball string gauge. A music store saler proposed me to replace strings with a large gauge. D'addario EXL 115W .011/0.49 saying it better suites for blues. It added that the neck might need to be fixed because of the larger gauge. Is anybody here ever tried that before? Is it worth going with that gauge? I play CCR, Blues, John Cougar, George Thorogood, old rock. What the "fix" part means?

Thanks in advance.
Epiphone Dot ES-335
Yamaha APX-500
Johnson acoustic
Fender FM 210R
He means the tension on the neck may result in it needing an adjustment later.

Whether it will or not is difficult to say and I'm not experienced with .11 guage strings or the 335 so I wouldn't like to comment.
Like adjusting the truss rod. It's really easy if you just take your time, and it shouldn't take to long. Just make sure you do it carefully, maybe read some instructions on how to do so ect.
If you don't feel comfortable doing so, then I'd suggest taking it to a tech and having them take a good look at it.