Since you aren't pushing yourself, go for things that will add layers of insulating air - a cape/poncho, a blanket around your legs (how cliché!), mittens instead of gloves (or over gloves), fur lined slippers instead of shoes, hood or scarf over hat.

The thin foil-like survival blankets sandwiched between layers really are amazing at keeping heat in.

If you have good sensation, you can go with some higher-tech solutions - like chemical warmers in your mittens/shoes.

Look into gloves targeted to winter bikers/climbers - extremely well insulated.