Queen Elizabeth Rose

I got three QE roses a year last summer and planted them in a garden on the outher hebrides. after they finished flowering i cut them back to approx 1 ft above the ground then last year only one came up. so i take it i managed to kill the other two.
However the one remaining one flowered again but rather than cut it back again i thought i would leave it so as not to kill it. but now as the spring is starting to come in it looks straggly and skinny is there anything that i can do ???? and what size can they reach.
tried to read up about them but i dont really understand prunning with all the cuts and heels etc

 

Don't be frightend of cutting it back Barra it will help to produce stronger shoots,next month just cut back to an outward facing bud put some fertilzer round it.