5+ hour train journey at 28 weeks?

Laura
I'm currently 27 weeks with Di/Di twins, I'd really like to go visit my family before they are born and was hoping to connect Wednesday when I will be 28 weeks.
So far I have had a fairly uncomplicated pregnancy, I had a irritable uterus at 20 weeks and was taken off work due to regular contractions but since then I have been fine, no issues at all.
So the question is would you go? 
It's a 5+ hour train journey with 1-2 changes and I would be travelling on my own with a 18 month old which I know makes things much harder.
On the other hand when I'm there I will have help with him and not have to look after my older 2/do the school run since they will be staying home with my partner who has work anyway so can't come with me.
The hospital where I'm travelling has a better facilities to deal with premature babies than my local hospital and in all likely hood if I did you in to labour at home now I would be transferred 4+ hours away anyway.
I will obviously be asking my midwife before making any decisions but would like the opinion of some experienced twin mummys too!!
Also I'm in the U.K if that makes any difference!!
Thanks!!