They will probably drown by then, if you leave them in water. I would wrap them in wet straw or shavings, in heavy paper or perforated plastic, and keep them cool, but not frosty, shaded, and moist until you are ready to plant.

or if you can put them in a rough and ready hole in the soil that too would suffice. they will die if left just in water.
if there are several sets then they can all go in the same temporary hole and cover with the soil. this is less than a 5 min task :o)
I did that with 6 bushes a few years ago and they are fine

welcome to GOY.

Agree with Tugb. they can't stay in water for that length of time. If you haven't got somewhere in the garden where you can heel them in, i.e. just dig a shallow hole dump them in and cover the roots with soil, then wrap as he has suggested.

Thanks you all so much. I'll not lose them now after your good advice! xx