As I was on vacation for about a month, without internet access, I have fallen too behind on my reviews to have any hope of catching up. I started over.

Since I have by no means forgotten all of my cards, would it be OK to push several hundred of the cards ahead a few stacks?(the ones that I'm REVIEWING[i.e. not forgotten yet? they used to be in the high stacks{so no damage will be caused i guess...}], as opposed to RELEARNING)...

I am wondering the same thing.

I reached 1350 kanji in June, then left my ideal study environment and routine and haven't reviewed since. Now all 1350 are due to be reviewed even though I'm sure I know hundreds of them.

What should I do?

You would have been better off just reviewing your large expired stack. You might fail a lot of them, but the ones you remembered would have stayed in high stacks. Why start over?

Eh, it's too late to not start over now.

I was about 1350 in, and my fail stack was about 250. It probably would have been about 600 when I finished. Also, the scheduling would be messed up.

Messed up as it was, it would have been better than starting over.

At this point, pushing them ahead is bad. Pushing cards ahead without really reviewing them will create a huge mess for you.

If you're going to start over, just start over. Do 50 or 100 per day for a while and deal with the large review stacks as they come.

Just take a few days a review them all without adding new ones. It won't be as bad as you think.

There's a clear moral to be learnt here (which I learnt the hard way):

NEVER TAKE A BREAK!

Not adding NEW kanji is acceptable, but you MUST review EVERYDAY.

or else you'll regret it later on....

Save holidays until you finish RTK :-)

Well...I was away from a computer --- a forced break.
I was very careful not to miss even a day. I missed one on the way, and it took a good little while to catch up.

I did that a few times. The first one when I switched to mnemosyne. The other one when I erased my deck by mistake. The third one when I mixed my RTK and sentences deck. Well, it sucked but I'm alive and kicking.