We have been very successful with conditioning the crawlspace. This process seals off the crawlspace and conditions the air to be closer to the air temperature inside the house.
For the walls, I'd recommend cellulose insulation applied in a drill and fill manner either on the outside of the house or the inside.
There are great monetary incentives for this type of work, not to mention the increased comfort and energy savings achieved.
For more information:
Read "I want to add wall insulation to my 1920 home. I have two locally available options -- Icynene and Tri-polymer foam. Can you advise me?" a Q&A answered by Alex Georgiou.