1) I think a Holiday Let would be accepted as non-business, business use being a different concept. I will not argue the toss about that, which you will inevitably start doing, as it doesn't matter in the slightest. See later. (I hope anyone else familiar or not with this troll will adopt my attitude in this thread. The OP wants help, not a fight between Bob_s2 and everybody else).
2) As per my previous post I believe the best option is Sky LLU Unlimited. (In the real world they would never know anyway. Nor would any other ISP the OP chooses).
Non-residential use would only be detected if, for example, a business were sending out large amounts of spam emails and complaints were received by the ISP about such emanating from one of its IP addresses.
3) The worst that could happen in the extremely unlikely event of an ISP alleging that its Terms and Conditions were being violated would be to cease the service. There is no possibility of the ISP taking legal action against the customer.
4) Re heavy use, that's what Sky LLU Unlimited all about.
My broadband basic info/help site - www.robertos.me.uk
| Domains,website and mail hosting - Tsohost
Connection - Plusnet
Extra Fibre (FTTC). Sync ~ 56.0/13.9Mbps @ 600m. - BQM
"Where talent is a dwarf, self-esteem is a giant."
- Jean-Antoine Petit-Senn.
Allergy information: This post was manufactured in an environment where nuts are present. It may include traces of understatement, litotes and humour.