So, I am looking at moving over to VDSL and I think Snap is going to be the ISP of choice.

My question is, within the next few months I am looking at moving house. I will of course look for a place where VDSL is available, but on the off chance it's not, would I be able to change back to an ADSL plan with Snap with no penalties? (I assume of course it would require me to sign another 12 month contract, but that's expected)