My advice
Try to shorten the script as much as possible.
I haven't seen that many mini-series on TV any more and I know I sure as heck don't want to wait all week for the next part.
USA and Sci-fi channel, and even HBO or other movie channels will run MOW or direct to TV films. This is often a good place to start for the newbie writer.
Still, these are feature length films (about 120 min) broken up by commercials.
Movies ARE being made in parts. LOTR and Kill Bill broke that mold.
Plenty of trilogies have been made.
These films are exceptions though, made by known people, from either stories with a built in following, or with strong stories sustainable over a long viewing time. Even then, the studios had MAJOR issues with the length.
At first LOTR was going to be only one film.
In my two examples each part has a strong beginning and end point.
You feel as though you've watched a complete story even though you know there is more to come.
When the audience is totally invovled in the story then, for the most part, we are willing to sit a little longer. Titanic was a great movie but it was long.
Seasbiscuit is a great movie but it is long.
You'll need to look at your script from all angles.
See if it can be broken up for commercials, if there are natural breaks every ten, fifteen minutes. Is there a natural break about page 120 or so where one half of the story comes to a satisfying end and then the rest continues with a good new beggining? And is sustained?
If you have to go to 140 or 150 to get to the end and then have 45 to 60 or 70 pages of wrap up or continuing story you will need to do some rearranging and repacing.
I don't know that much about you, so far your posts have seemed very reasonable and inteligent so I assume you know and understand a fair amount.
Still, keep your mind open to the possibility that there could be more to cut then you are willing to see.
They don't call it killing your babies for nothing.
Let me make sure I am understanding you correctly.
You look at your dialoge and even though you like it all and it sounds good to you, still you have this nagging sense that maybe that is where you should cut?
That seems reasonable to me.
Go through it again. See if there are places where a look or an action can replace some lines. See if you can tighten up a few lines, maybe take out some fluff, overly polite or too perfect words.
Many times the dialog of some characters is written in "correct english" when that charcter, most characters, wouldn't talk that way.
See if there are scenes that would be more powerful if done in silence.
There are little tricks for shortening up the script.
Honest ones, no, not cheats Joe.
Search through the script for widows, or orphans. (one word taking up one line)
Look for lines that can be tightened up by fragmenting the sentence.
John grabs the gun that he had set on the table, and then cocks it, and points the buisness end at Martha
could be shortend to John grabs the gun, cocks it, aims at Martha.
Take out any uneccessary parenthecticals.
If you've got lots of action lines that are only one or two lines long see if you can combine them. If you've been forcing yourself to only write in a 3 or 4 line blocks then go up to 5 BUT not too often.
All those blank lines can really up the page count.
Keep in mind that the script STILL needs to be open.
It's a very delicate balancing act. Something that you can play with though.
60 pages is a lot but, every little bit helps.
Post some of your pages. Maybe we can help you out more.