So.... my T is moving and I know sensibly it's probably too far to travel and actually with the amount of dissociation I can get after a session, it's not the safest option either - which means either we decide to end it
I was in a situation somewhat like this, and here it what I learned from it.
First, as much as I thought the therapy was helping me, even though I was dis-associative afterwards, it really wasn't. Exposure therapies (be it EMDR or talk therapies that trigger issues) walk a fine line; they need primarily to provide a safe foundation. Regularly, if the therapy lands me in an emotionally unstable state, when I walk out the door, it is my job to ask the therapist to make an adjustment to therapy, and it is the therapists job to make the adjustment.
I told my therapist of my dis-associative problem, after sessions. My therapist verbally said he would make an adjustment, but behaviorally, he didn't. I believed the verbal part, just like I did my abusive parents and abusive boyfriends. What kept me going was that I behaviorally was demonstrating that I was gaining some skills.
However, and most importantly, I was NOT gaining confidence in myself, because my therapist was dis-respecting my boundaries/not recognizing that his treatment was a bit too much. (His ego needs to drive therapy his way were greater than his ability to listen to and incorporate my needs. When I brought my concerns up again, he would appear to listen, but turn them around, to being my issues.
I hate to stop relationships, for all the reasons most people do. Going through change (e.g. a loss-even of an unhappy, or uncomfortable situation) seems to be a big trigger in itself-that acts as a deterrent to leaving and moving on, to something better.
When it came time, for me to physically move, we started Skyping. As was mentioned in the responses above, I got some help from techie friends and practiced. Since I couldn't rely on the wifi system at work, I got the 'hotspot' function on my smartphone-that acts like a wifi system, that my computer can link into. It was a little problematic, and I got it to work.
Due to a breach of confidentiality, of someone over hearing our session, behind a closed door, that created havoc for me, I stopped doing Skype. Due to not having any sound-proof walls or doors anywhere (work or home), my therapist and I opted for phone conversations, where I knew no one was overhearing me-(e.g. In my car, walking with no one around, etc.).
A great benefit of being away from my therapist was that I was not triggered as much, and hence, less dis-associative, after our sessions. The distance of phone calls gave me more distance, which helped me feel safer, and it gave me the courage to challenge my therapist, bit by bit-to not trigger him too much. If what he was saying was triggering to me, I could hold the phone away from my ear. In the long run, I came to understand, that I would be better off to find another therapist, and I did.
I found that being finding a better therapist before I ended the therapy with the first therapist, really helped me be able to let go of the first therapist. And initiating finding the new therapist put me in the 'active role', rather than habitually being in the passive role of loss, that is very triggering.
Skype and phone calls, I'd only do them on a secured wifi, and with soundproof doors and windows.
Good luck.