May be nothing to do with the snow. Laminitis can be initiated by so many different things. In my horse it was emerging encysted small red worms. They only show up in a blood test not a worm count. Your vet needs to determine what caused this incident of Laminitis.
The only way you are going to resolve this issue is by ensuring that the field your horse is in is completely poo picked each and every day. This will also improve the grass as poos lying on top of grass kill the grass and then weeds (thistles, docks and ragwort take over).
If your yard owner...
If this is the Mid Wales Railway Line then there was nothing unusual for animals to travel on the train to and from the markets years ago. Welsh Mountain Ponies would happily travel on the trains. Under the Beeching plan they attempted to close the line but it went through so many marginal...
I am looking for a reputable person/company to build me a very basic 3 horse horsebox on a 7.5 Ton chassis. Rear Ramp/Herringbone. No living just space for tack. i.e Hunting/Racing Type. As close to Herts/Cambs/Essex area as possible. Any suggestions?