Cheap and Cheerful:
Hatfield and St Albans have many Holiday inns, Premier Inns and Travelodges. The closest to the venue is Hatfield Travelodge. but the St Albans City centre hotels are nicer and in the city which is lovely
https://www.travelodge.co.uk/hotels/321/Hatfield-Central-hotel
Slightly nicer:
The Comet Hotel is very close to the venue and is in a really cool building
Luxury:
if you really want luxury then Sopwell house is the place to stay