I got on fine with my mother in law, we never had any arguments or anything but ever since my partner and I decided to buy our first home she has been a nightmare.
It's not just this one incident but I will use it as an example...
We have a LOT of stuff to move into our new house and she is insisting we make about 100 trips with her car and trailer. I appreciate the thought but we are getting a moving truck. I have talked to her about it and so has my partner but she won't take no for an answer, now she has organized my partners grandfather to bring his SUV up from his place which is 4 hours drive away!
Has anyone else had similar problems? And how did you deal with it? Talking to her is like talking to a brick wall. It's becoming a real problem and it seems she wants to control everything we do now that we are moving away (Our new house is only 15 minutes drive away anyway!)

Seeing that you have a good relationship with her and she obviously means to be helpful- how about throw her a bone? I mean, explain to her that you've arranged for a moving truck to transport your things in one trip because you prefer to get that part done quickly. Perhaps ask her to help with some of the smaller jobs like helping to set up the kitchen or unpacking the living room. It'll make her feel useful and sounds like she'd be more than happy to help you.

I am going the same thing with my future mother-in-law. I would say I had decent relationship her but ever since I starting planing my wedding she wants to control everything. I tried talking to her and explaining nicely that this day is very important to me and even though I value her input I'll be have the last say so in things but she stills tried to take over until I got fed up and not let her put anymore input. She doesn't know how to not be controlling and step aside.

Me and my fiancé talked to her about it, together and sperately, but it went in one ear and out the other. Now we have a strain relationship but I feel and know I did nothing wrong but expressed myself to her in a nice firm respectful way.

Sometimes she people don't know how to step aside and if you don't put your foot down she'll continue taken over. Everyone Loves Raymond comes to mind. So in order to deal with her you have to continue being patient but firm.

This moving situation should be handle the way you se best and want it to. Moving every thing at once instead of making mulitple trips sounds better and less time consuming. But not only must you stand firm on this issue your husband must put his foot down too because it is his mother. The two of you must work together as a team to battle his mother controlling ways.

So you arrange the moving crew, rent the truck and just do it,

At some point there will be 100 opinions, what you and partner wants to do is what you do.