To get back to what you were <i>actually asking</i>: you can do intervals on any stretch of flat road, or on hills, if you want to do hill repeats.

Do spin-ups of a couple of cadence rpm per time interval over any periods of your choice, or you could do high gear slow to fast accelerations, and loads of hill repeats.

I live here in New York, and it's comparatively colder... I'm planning on selling my stationary trainer because, well, they are horrible. Two hours on the road is more pleasant and satisfying than 10 minutes on the trainer.

Just get out there, and do your intervals on some open road. You'll be better for it.

Getting lights is money better spent, IMHO, but if you do want a trainer, get the fluid trainer. They have a better feel to them than magnetic trainers, and are quieter than wind trainers. They are not cheap, but you can get them used in the spring all over the place. I got a basically unused Cycleops Fluid2 for under $100 in June (Everyone realizes in late spring how much trainers suck, and get rid of them unless they are masochists.)

Just my 2 cents, YMMV, yadda yadda. Good luck.