2x17 miles is quite long but quite do-able.
If you allow yourself 1.5hrs to start with you will be able to judge your time and leave later.
Carry spare insulation/waterproofs as required. A small waterbottle, puncture and basic toolkit, small road-rash first aid kit,
Keep a heavy lock at work but carry a cable lock for popping into shops.
Add F/R lamps and reflectors, fenders if it gets wet.
Wear bright clothing, helmet and gloves and cover your legs up in the cool.

You can carry the stuff in a large saddlebag, racktop bag or single pannier.

The most appropriate tyres are probably 25-28mm kevlar-banded fairly slick. You only need tyre tread off-road.