Rooted strawb' runners.

I've done the same, Klefters, and most are already in the GH.

I think I'll grow them at waist height in a long deep gutter (they're Alpines), as picking them is a bit of a bind so low down!

I think strawbs are one of the plants that need a cold winter period to grow and fruit well next year.
The trouble is with most amateur glasshouses is that on sunny winters days they can heat right up and then go down to minus temperatures in a couple of hours and this can be repeated many time over the winter period.
IMO not many plants enjoy these big temperature swings.

Not sure what the commercials do in the polytunnels but i would expect very good ventilation to avoid temperature build up is a must till they want the plants to get set for early fruiting.