We have a beefsteak that is probably 8 feet long if it was standing upright and covered in tomatoes. The cherry is easily that long and has multiple stalks with 12-15 blooms on it and it's already fallen over twice. The others (heirloom and big boy) won't stand at all if I remove the stakes that hold them. Some of them have crawled into the wire (stapled outside the grow beds) that the cucumbers are vining up into and are doing well. I can wire up the rest but it will make harvesting rather a pain in the rear.Certainly possible, I wouldnt bother though. They are in flowering mode, why negate that? Cutting and replanting will delay them by a few weeks for sure. Not all of the blossoms will set anyways, and if its hot where you are, it will be even less. Blossoms dont set in hot temperatures. I'd find a way to support them if it were me. Bambo stakes, twine, etc and "make a cage". Are they getting enough sun? Plants tend to stretch if not enough sun. Some varities, paste tomatoes and heart tomatoes, are just naturally "spindily." They have what is reffered to as Wispy leaf foliage. Naturally, thin, droppy and frail looking even when healthy. Let the plant tell you it cant hold the fruit up, it may be just fine as is.