Hey Sogoak- thought I'd cruise the questions and found yours here. Note there are several technical solutions posted all over the Internet by home guys with nearly a PhD in brewing. As a non-chemist brewer, lemme see if I can help:
First, specific lagering procedures are as diverse as the lagers on the liquor store shelf. As you've demonstrated, the yeast manufacturer should always be your first resource for temp ranges, but there is some leeway. Though you want to maintain consistent or gradual temp changes with any brew, this is rarely possible in the average HBr's home- so don't sweat your situation.
It doesn't sound like you've harmed the yeast, but a good rule of thumb I follow is hold your lager at room temp for one to two days before lagering. This ensures the yeast get a good start as even lager yeast propagate more quickly at higher temps. After this initial period, anything goes without a fridge to cool the brew, but given your situation I might move the wort into the basement for a week and then into the walkout for a week or until fermenting stops. It's always helpful to take gravity readings, but if you're not at that point, pay attention to the airlock activity and make your best guess. At this point do the diacetyl rest for 24 hrs. Then transfer into a secondary and lager in the walk out. Depending how soon you'd like to consume the beer, you could give it a month or until spring breaks the winter cold.
Lagers always taste better with time. I have a couple that are 10 months and eight months respectively and they get better every day. Good luck and post any other questions. Dman