Install larger gray tank??

We are pretty new to RVing and have concluded a Calif/Colorado loop recently. So far, the main lesson I have learned, I think, is to avoid RV parks and dry camp in parking lots. Having a 24' Mallard trailer, our two main limitations are no generator and a smallish (40G?) gray water tank.

Is it feasible to install a larger gray tank? Has anyone here ever done such a project? I tried to view the underside of the trailer, but it's pretty well sealed with netting of some kind.

Am I nuts to want to stay in consenting owners' parking lots such as walmart?

Thanks for any comments or suggestions.
Install larger gray tank??

I think 40 gal is about standard, maybe even large for a grey tank. Remember, all those gallons equals weight, about 8 pounds per gallon. I'm courious, why do you want to avoid RV parks?
Install larger gray tank??

Maybe a thread about RV park pros and cons would be a worthy one, but did you ever switch out a gray holding tank? I'd sure like to know of someone who has or decided it wasn't worth the effort. Surely it would be cheaper than moving up to a motor home! (Even though I'd like to.) I want a couple of days worth of tank capacity so I'd just have to dump about that often.
Install larger gray tank??

No, I never have, nor have I heard of anyone doing it. (That dosen't mean it hasen't been done!)

I would be very careful when changing engineered components. (i.e., the tongue may not be designed for the additional weight a bigger tank would incur, or any number of other variables).

Good luck!