I've got the same problem and am at this very moment trying to do a work around. I'll offer a pre-tour page with links to hi and lo res version. I'll also offer some info on the tour and explain about java and file size and having a bit of patience with 56kb. The Hi res links to 150-200kb 300x400 map and thumbnails. The lo res leads to 80-120kb 225x300 images without thubnails. I also tend to have no pano hotspots... just map hotspots. (I tend to do this for most of the Realestate tours following feedback from users that map links only are easier for newbies to cope with)
Now my workaround. Build your hi res tour as per usual and save. reopen vtp in TW and exchange the viewerskin to the smaller one and exchange thumbnails for list box. Remove all the panos and import new lo re versions. (here I hope that the map feature won't need redoing (btw, all the names of the lo res images are the same as are dimensions.) Publish. This should work and I'll report on this later in the day and do a show and tell/test. It's a little bit of work but not more the 20 mins and should result in the desired effect. (Alternativly u may just be able to change the images in the scene folder of the completed tour.
Here goes... I'll report later today.
If I only had an hour to chop down a tree... I'd spend 45 mins sharpening the axe.