Is the quest "the reunion' the opening of Lonesome road? I recently bought the ultimate edition of New Vegas because it's one of my favorite games, but I everytime I go to the divide to enter the script tells me this is a a road I have to take myself and cannot bring a companion. So I took the robot dog back to my apartment in Novak- but it still prevents me entering.

The divide is by the canyon wreckage, in case I've mixed something up. Do I have to get rid of all of my companions? Or is this a glitch I can fix?

There is a console on the outside of the Gun Runner's shop, it is a companion dismissal terminal. You have to dismiss all of your companions and they will return to where you found them, or to wherever you have them stashed.

Like the above poster says, I'm used to all DLC's forbidding companions that you need to manually dismiss first.
I would advise preparation to keep in mind carrying capacity for just your main character to haul the loot as a result of completing LR (and the other DLC's).

Well, it's called LONESOME Road for a reason! Yea, you need to dismiss all your companions, before you can enter it. Once you enter, you can return to the Mojave anytime you want (sell loot, get more ammo etc). It's a harsh road, physical and emotional... it's amazing though, despite everything!

Lonesome Road is amazing and powerful, I made the mistake the first time playing this DLC first, but later found it a lot more rewarding after playing the other DLCs first. I would say exactly why but I don't want to be spoilerific.

Yea, during my first play through, I actually did Lonesome Road first. I had NO idea that all these DLCs were sort of connected! This time around, it will be last on my list.

I actually enjoy doing LR before the others. I like prequels, and reading a story about "how we got here".

As a challenge yourself kind of challenge, in one of my recent pt's I did it at lvl 4.. (when I left I was lvl 15.. )
I did build my character so I could cope.. and not on hardcoe... it is a challenge (yes I had to tone it down to hard...and in some places normal) but because you don't have decent weapons (starting), crappy armor... limited ammo, nearly no health items.. It is a steep but fun challenge..
I have to say though that the DC's and the tunnelers... are way more manageable than when you start the DLC at let's say lvl 40... decent gun skill combined with a riot shotty will do wonders as wel as the sniper rifles you find in the Divide. (obviously for the DC's)
But the marked men are remarkably tougher on a low level.. which is not that weird...as they start out with their standard armor.... and mid tier to high tier weapons...
(unlike OWB for example... where the lobotomites are levelled, do have a high DT but no armor to speak of and start out with lower tier weapons..)

OMG you are a brave guy! LOL At level 4!!!!!!!!! I did it on level 28 and on EASY and it was still tough as heck! LOL Hats off to you! I also gained several levels in the Divide. So, yea I was wondering, the DCs and stuff level with you then?

Like I said the DC's and Tunnelers seem to directly level with you.. (thus can be managed, I would argue they are even easier on lower levels....) the Marked Man are nightmarish...
Getting through the first silo and Hopevile took me four times longer than on previous PT's... and dying at least a gazillion times.. After the highroad... things get better.. (decent gear... more ammo... etc...,and tada MRE's )
(example: I usually have decent points in lockpicking and science due to being above lvl 26 doing previous pt's. So I nearly never ever have to fight the sentry bots in the hopevile silo... Not now... at one point I was actually like... ok this is not doable.... but sneak criticals and pulse slugs will do wonders.. (GRA))

Doing this on hardcoe (especially hard/very hard) would be a real challenge and extremely difficult... (but I am sure there are people who have actually done this..)

Im gonna do this as soon as i have set things straight (just finished OWB) in the Mojave, and buy a few guns (im lvl 27) and ammo and ALOT of stims. hardcoe, very hard and with as many weapons, ammo, stims, meds and [censored] i can take. And gonna establish a safehouse there so i dont have to go back EVERY time i am full, cause i dont wanna take chances on getting stuck and deying alot of times (happened a few times in OWB)

Lvl 27 VH/HC should be doable.. What I'm talking about is straight out of Goodsprings.. or just a few lvls in.. Little to no gear.. little to no stimpacks and voila.. My feeling is that it will be near impossible.. (on vh/hc I feel the sweetspot to be doable should be around lvl 10-15)

Yeah... might be fun to try, but doing lonesome road first kinda kills it i am thinking. I′ll probably try it out sometime, when im making a new safe.