How long will a subway sandwich stay good in the fridge?

if I buy the two subs for 8.99 then eat one today will the other one stay good till say tuesday for dinner? or is that pushing it...

Eat one 6 inch tonight and the other one tomorrow night and you will be fine. I would not push it till Tuesday...
Enjoy!

after a couple hours they become sogie..

3-4 days.

I think it will be gross by then. I don't even like them a few hours later...but that's just me.

The veggies on it will wilt, yuck!

I've kept them that long, but the veggies do wilt.
If you want to keep one that long, some tips:
Don't get dressing
Ask them to put the veg on the side, they usually will
And don't get one of the salads (tuna,chicken)
Also, make sure to wrap it in plastic when you get home, or your bread ends will get dried out.