Will 700MHz LTE be Verizon's Achilles Heel?

We all know that, right now, Verizon's LTE is unmatched in the USA.

However, the potential problem I see is this being saturated soon.

Unlike their CDMA network which runs on 850MHz (covers larger areas
better) and 1900MHz (can have advantages in highly populated areas),
Verizon's current LTE phones only use the 700MHz band for LTE.

To oversimplify things, 1900MHz towers need to be more closely spaced
(a disadvantage), but can provide more bandwidth (an advantage)
because less users are using each tower versus if there was only
850MHz ones.

Again, to oversimplify things, Verizon's CDMA network puts 850MHz
towers to cover the nation and then places 1900MHz towers in places
where there is high concentration of users. Of course, this depends
on where the FCC has granted Verizon licenses, but the principle is
still there.

What is Verizon going to do if these 700MHz towers become saturated?
Do they have a "Plan B"?

The obvious answer is to start NOW in transitioning out of their CDMA
network, like they did with AMPS (and AT&T did with AMPS/TDMA). Make
EVERY fone they sell support LTE (in the hopes of going to
Voice-over-LTE) in the future.

The big question: Does Verizon have the cojones to do this? Does
Verizon have the balls to tell grandma with her 10 year old CDMA2000
fone that it's time to move to 2011?? Does Verizon have the guts to
take their 850/1900 CDMA equipment, throw it in the trash and replace
it with 850/1900/700 LTE ones?

I doubt it...