Winterize new T@B 400 2017

I took a post from JohnDanielsCPA and turned it into a checklist for winterizing my 400.  He uses the “blowout” method.  I’ll figure out the locations for valves and drains when I winterize my camper today.  Here is what John says (I’ve edited his post to meet my needs.  Here is the page where his original post appears - http://tab-rv.vanillaforums.com/discussion/5866/winterizing-methods-revisited/p3):

“T@Bs are very small trailers that don’t have a lot of tubing.  If you blow out the lines with at least 40psi pressure, you are going to blow out enough water to virtually eliminate any risk of damage.  Water does not expand THAT much when it freezes, so if there is a little bit left in the lines, you aren’t going to have a problem.  Water lines break when water freezes and it has nowhere to go.  The little bit of water likely left in the lines after blowing them out will not expand enough to break them. 

1. Make sure you drain the Alde; yellow lever flipped up; and leave it up.  Open your low point drains, then run your compressor through the city water connection.  
2. Open each faucet (hot then cold for kitchen sink then shower) and flush your toilet so the water is cleared from the toilet valve.  
3. If you have an outside shower, make sure you clear that as well.  Give the compressor time to push most of the water out; it doesn’t have to be every drop.  
4. Finally, run your water pump for a few seconds.  Unscrew the filter and drain any water that may have collected there.  Some water may drain out of the pump when you remove the filter, but it won’t be enough to be concerned with.  
5. The drains (shower, sink and toilet) need to have antifreeze dumped down them; not a lot, maybe a cup at most for each drain.”

We just purchased a T@b 400. It was winterized. We are planning a trip south this month. We will need to dewinterize once south and winterize before returning. Planning on not using freshwater tank or pump. Will use city water hookups. So...we will drain everything  and do the blowout or antifreeze method. Our dealer strongly recommends antifreeze method. My question given our use, can we leave out the step about the water pump? I assume we would get one of those hand pumps to fill the city water lines with antifreeze. Am I missing something?

If I recall corectly, the 400 has a really nice winter bypass switch on the driver side in an outside compartment. This is different from the 320, so please check your manual.

our 400 came only with a "T@B manual" which is not specific for the 400 - all the diagrams and pics are for the 320... what does the bypass switch do?